Based on researches of the crop potential productivity,the potential productivity of light,temperature,water and land from wheat in China were calculated respectively,and converted into the potential productivity of w...Based on researches of the crop potential productivity,the potential productivity of light,temperature,water and land from wheat in China were calculated respectively,and converted into the potential productivity of wheat straw according to the coefficient of grain-straw ratio of wheat.Furthermore,based on the wheat planting area in 2006,the potential yield of wheat straw fiber in China was estimated.The results showed that the potential yield of wheat straw fiber in China could reach 94.91 million ton,which could provide evidence for the further potential analysis of bio-ethanol.展开更多
[Objective]The aim was to study the effects of regulation of C/N ratio wheat straw application on tobacco nitrogen,phosphorus and potassium uptake. [Method]Effects of regulation C/N ratio wheat straw application on th...[Objective]The aim was to study the effects of regulation of C/N ratio wheat straw application on tobacco nitrogen,phosphorus and potassium uptake. [Method]Effects of regulation C/N ratio wheat straw application on the flue-cured tobacco yield,output value,nitrogen,phosphorus and potassium content and cumulative uptake of the upper,middle and bottom leaf were studied by using the field plot experiments at Banqiao town,Qujing city,Yunnan Province during the 2008-2009 summer growing seasons. [Result]The results showed that the application of wheat straw alone or after C/N regulation,could significantly increase tobacco production,potassium content,the potassium and nitrogen accumulation amount of leaf,and was more conducive to the potassium uptake of tobacco leaf with wheat straw application after C/N regulation. Compared with non-straw application,the yield of tobacco increased by 6.59%,3.58%,5.98%,8.80% with application of wheat straw alone,wheat straw and vetch,wheat straw and oilseed cake,wheat straw and urea nitrogen,the potassium content in tobacco leaf increased by 3.85%,7.76%,8.82%,11.21%,respectively,the total potassium cumulative amount of leaf increased by 10.71%,11.62%,15.32% ,21.01% and the total nitrogen cumulative amount increased by 9.76%,1.22%,8.14%,14.00%. However,the differences of tobacco leaf nitrogen content among the different treatments were not significant,the phosphorus uptake of tobacco leaf decreased. [Conclusion]application of high C/N ratio wheat straw in flue-cured tobacco production,which should be concerned not only to adjust C/N ratio by adding nitrogen,but also considering additional phosphorus application.展开更多
In order to study the effect of rice straw returning and seeding patterns on seedling emergence and grain yield, field experiment was conducted to investi- gate the effects of straw mechanized returning and different ...In order to study the effect of rice straw returning and seeding patterns on seedling emergence and grain yield, field experiment was conducted to investi- gate the effects of straw mechanized returning and different seeding patterns on e- mergence rate, emergence uniformity and yield traits of wheat after rice. The results were as follows： in rice straw removal treatments, the emergence rate of mechani- cal seeding in drill was lower than that of mechanical uniform planting and manual broadcast sowing, which were 51.84%, 90.89% and 88.87%, respectively; the emer- gence uniformity of manual broadcast sowing was inferior to mechanical seeding in drill and mechanical uniform planting, which were 0.49, 0.26 and 0.23, respectively. As for the treatments with rice straw returning to the field, the emergence rate and emergence uniformity all decreased in the three seeding patterns, of which mechan- ical seeding in drill dropped markedly with emergence rate decreased by 36.54%. The emergence rate and emergence uniformity affected grain yield by affecting pan- icle, grains per spike and 1 000-grain weight. The grain yield for the treatment with rice straw removal was 6 091.34 kg/hm2, while that with rice straw returning to field was 6 476.20 kg/hm2, and both were higher than the yields of the other two seed- ing patterns. Therefore, mechanical uniform planting was？recommended for its higher emergence rate, better emergence uniformity, which was conductive to increase grain yield in wheat after rice production with rice straw returning to field.展开更多
Objective] The aim was to study the effects of cotton straw extract on wheat root growth and define the al elopathic effect of cotton straw on wheat root. [Method] A sand culture experiment was conducted under differe...Objective] The aim was to study the effects of cotton straw extract on wheat root growth and define the al elopathic effect of cotton straw on wheat root. [Method] A sand culture experiment was conducted under different cotton straw ex-tract levels （0%, 1.0%, 2.0%, 4.0%, 8.0% and 10.0%）, and the morphology and physiological activity of wheat （Yangmai 13） root were studied. [Result] The cotton straw extract inhibited the elongation of wheat roots, but increased the root diame-ter, resulting in the decreased root surface area and volume; The extract treatments induced the increase of root reactive oxygen species （ROS） level, which led to an increased root membrane lipid peroxidation, thereby reducing the root vigor and in-hibiting the root water uptake and formation of biomass; With the increase of con-centration of cotton straw extract, the total phenolic acid content in the extract in-creased continuously, and the total phenolic acid content was closely related to the morphogenesis and physiological activity of wheat root. [Conclusion] The cotton straw extract inhibited the morphogenesis and physiological activity of wheat root through affecting the root ROS level, and the total phenolic content was one of the main limiting factors.展开更多
[Objective] The aim was to investigate the application effect of swine manure-straw returning and to determine the best mode. [Method] A field experiment under rice and wheat rotation with different swine manure-straw...[Objective] The aim was to investigate the application effect of swine manure-straw returning and to determine the best mode. [Method] A field experiment under rice and wheat rotation with different swine manure-straw treatments was con- ducted to study the growth characters and output of rice and wheat, calculate the economic benefit and carbon dioxide emission reduction, and analyze the best mode of swine manure applying-straw returning. [Result] The swine manure-straw returning was conducive to the growth of crop, the highest outputs of rice and wheat were on the treatment of ＂30% swine manure and 20% straw and 50% chemical fertiliz- er＂, they were 7 874.57 and 6 427.00 kg/hm^2, and saved cost about 5 146.35 Yuan/hm^2, increased input 5 312.56 and 3 931.93 Yuan/hm^2, the greenhouse gas e- mission reduction was 1.30 t/hm^2 （calculated according to carbon dioxide on a dry basis）. [Conclusion] The treatment of ＂30% swine manure and 20% straw and 50% chemical fertilizer＂ was the best mode of swine manure-straw returning.展开更多
A case study of Jiangsu Province was conducted using questionnaires and field survey to explore the status quo of the collection and utilization of rice and wheat straw of the province. Problems in collecting the stra...A case study of Jiangsu Province was conducted using questionnaires and field survey to explore the status quo of the collection and utilization of rice and wheat straw of the province. Problems in collecting the straw were analyzed taking into account meteorological data of the rice and wheat harvesting seasons in the region. Results show：（1） Currently, the main handling way of rice and wheat straw was directly returning to field. The peasant households of straw returning from investigated townships A and B respectively occupied 22.01% and 28.75% of investigation households, and both of the two townships had a considerable portion of the straw wasted or improperly disposed. In township B, over 50% of the farmer households surveyed failed to make sure of any of the straw, and as high as over55% of the straw was discarded or burnt.（2） During the rice and wheat harvesting seasons, the ten-day precipitation was among 7.21-87.28 mm, and the ten-day precipitation days were among 1.53-5.00 d. Such weather not only affected timely harvesting of rice and wheat, but also seriously impeded baling, transportation and storage of straw.（3） As the crops must be harvested in a relatively short and concentrated time period, large volumes of straw were turned out within a few days.Moreover, harvesting of the first crop often coincided with sowing, leaving little time available for straw collection.（4） Straw collection was very low in economic benefit.A farmer can only get 60-90 RMB per day from straw collection and transportation,which was much lower than what they can get by working as migrant workers in the city.（5） Machines designed for straw collection were rare and those now used in the operation were low in efficiency and needed to be improved technically,which directly affected the efficiency of straw collection. The above-listed findings indicates that time shortage, negative weather condition, low benefit and low mechanization level were major factors affecting straw collection. To solve the problems,the following proposals were brought forth, that is, improving the economic benefit of straw collection as a driving force, accelerating the research and development of rice and wheat sheaf-binding reaping machine, and setting up a long-term operational mechanism for straw recovery, in the hope that this study may provide some useful ideas to help solve the problems.展开更多
[Objective] The aim was to improve the adhesive bonding property of wheat straw surface to prepare wheat straw particleboard of soy protein isolate （SPI） adhesive through chemical and enzyme treatments. [Method] Eva...[Objective] The aim was to improve the adhesive bonding property of wheat straw surface to prepare wheat straw particleboard of soy protein isolate （SPI） adhesive through chemical and enzyme treatments. [Method] Evaluation and analysis were made on wettability of wheat straws in the control group and treated groups （chemical and enzyme treatments） by means of measurement of contact angle and calculation of spreading-penetration parameters （K）. In addition, we made analysis on surface elements through X-ray photoelectron spectroscopy （XPS）. [Result] The re- sults showed that K value of straw treated with sodium hydroxide, hydrogen peroxide and lipase increased by 58.0%, 48.7% and 83.2% compared to that of control group, respectively. The XPS analysis indicated that rapid decrease of silicon content and destruction of wax layer greatly contributed to wettability improvement of wheat straw surface. [Conclusion] The chemical and lipase treatments of wheat straw provided technical support for manufacture of wheat straw particle boand.展开更多
Straw return is an important management tool for tackling and promoting soil nutrient conservation and improving crop yield in Huang-Huai-Hai Plain, China. Although the incorporation of maize straw with deep plowing a...Straw return is an important management tool for tackling and promoting soil nutrient conservation and improving crop yield in Huang-Huai-Hai Plain, China. Although the incorporation of maize straw with deep plowing and rotary tillage practices are widespread in the region, only few studies have focused on rotation tillage. To determine the effects of maize straw return on the nitrogen （N） efficiency and grain yield of winter wheat （Triticum aestivum L.）, we conducted experiments in this region for 3 years. Five treatments were tested： （i） rotary tillage without straw return （RT）; （ii） deep plowing tillage without straw return （DT）; （iii） rotary tillage with total straw return （RS）; （iv） deep plowing tillage with total straw return （DS）; （v） rotary tillage of 2 years and deep plowing tillage in the 3rd year with total straw return （TS）. Treatments with straw return increased kernels no. ear-1, thousand-kernel weight （TKW）, grain yields, ratio of dry matter accumulation post-anthesis, and nitrogen （N） efficiency whereas reduced the ears no. ha-1 in the 2011-2012 and 2012-2013 growing seasons. Compared with the rotary tillage, deep plowing tillage significantly increased the grain yield, yield components, total dry matter accumulation, and N efficiency in 2013-2014. RS had significantly higher straw N distribution, soil inorganic nitrogen content, and soil enzymes activities in the 0-10 cm soil layer compared with the DS and TS. However, significantly lower values were ob- served in the 10-20 and 20-30 cm soil layers. TS obtained approximately equal grain yield as DS, and it also reduced the resource costs. Therefore, we conclude that TS is the most economical method for increasing grain yield and N efficiency of winter wheat in Huang-Huai-Hai Plain.展开更多
In northern China, the soil-born diseases of wheat have been getting more and more serious under a new farming system that returns maize straw to the field. In order to investigate the allelopathy of the decomposed ma...In northern China, the soil-born diseases of wheat have been getting more and more serious under a new farming system that returns maize straw to the field. In order to investigate the allelopathy of the decomposed maize straw products on three soil-born diseases of wheat, culture dish and pot experiments were conducted and the compounds in the products were identified by gas chromatography-mass spectrometry （GC-MS）. Culture dish experiments showed that the mycelial growth, sclerotia formation amount and total weight of Rhizoctonia cerealis were promoted at concentrations of 0.03, 0.06 and 0.12 g mL-1 and inhibited at concentration of 0.48 g mL-1 of the decomposed products. No significant effects were found of the product concentrations on average weight of the sclerotia. Mycelial growth of Gaeumannomyces graminis was promoted at almost all concentrations except the highest one. Mycelial growth and spore germination of Bipolaris sorokiniana were significantly inhibited by all concentrations of the decomposed products, with enhanced inhibition effects along with the increased concentrations. The length, number and dry weight of roots together with the root superoxide dismutase activity were promoted by the lowest concentration （0.03 g mL-1）, with a synthetic effect index of 0.012, and inhibited by other concentrations. The ion leakage of roots was increased and the root peroxidase activity of roots was lowered by all the treatments. Pot experiments revealed that occurrence of the sharp eyespot was reduced by 0.03 and 0.06 g mL-1 of decomposed products after irrigation. However, the incidence rates and disease indexes were significantly increased by 0.12, 0.24 and 0.48 g mL-1 of decomposed products. The results indicated that incidence rates and disease indexes of the take-all were significantly promoted after being irrigated with the decomposed products, while occurrences of the common rot didn＇t change, significantly. GC-MS results showed that the compounds of the decomposed products included organic acids, esters, hydrocarbons, amides and aldehydes, with the proportions 25.26, 24.01, 17.22, 14.39 and 7.73%, respectively. Further analysis investigated that the allelochemicals identified in straw decomposed products contained p-hydroxybenzoic acid （9.21%）, dibutyl phthalate （6.94%）, 3-phenyl-2-acrylic （5.06%）, 4-hydroxy-3,5-dimethoxybenzoic acid （2.26%）, hexanoic acid （1.73%）, 8-octadecenoic acid （1.06%）, 3-（4-hydroxy-3-methoxy-phenyl）-2-propenoic acid （1.04%）, 4-hydroxy-3-methoxy-benzoic acid （0.94%） and salicylic acid （0.94%）.展开更多
The incorporation of straw in cultivated ifelds can potentially improve soil quality and crop yield. However, the presence of recalcitrant carbon compounds in straw slow its decomposition rate. The objective of this s...The incorporation of straw in cultivated ifelds can potentially improve soil quality and crop yield. However, the presence of recalcitrant carbon compounds in straw slow its decomposition rate. The objective of this study was to determine the effects of different nitrogen sources, with and without the application of zinc, on straw decomposition and soil quality. Soils were treated with three different nitrogen sources, with and without zinc： urea （CO（NH2）2）, ammonium sulfate （（NH4）2SO4）, and ammonium chloride （NH4Cl）. The combined treatments were as follows：maize （M） and wheat （W） straw incorporated into urea-, ammonium sulfate-, or ammonium chloride-treated soil （U, S, and C, respectively） with and without zinc （Z） （MU, MUZ, WU, WUZ;MS, MSZ, WS, WSZ;MC, MCZ, WC, WCZ, respectively）;straw with zinc only （MZ, WZ）;straw with untreated soil （MS, WS）;and soil-only or control conditions （NT）. The experiment consisted of 17 treatments with four replications. Each pot contained 150 g soil and 1.125 g straw, had a moisture content of 80%of the ifeld capacity, and was incubated for 53 days at 25°C. The rates of CO2-C emission, cumulative CO2-C evolution, total CO2 production in the soils of different treatments were measured to infer decomposition rates. The total organic carbon （TOC）, labile organic carbon （LOC）, and soil microbial biomass in the soils of different treatments were measured to infer soil quality. All results were signiifcantly different （P〈0.05） with the exception of the labile organic carbon （LOC）. The maize and wheat straw showed different patterns in CO2 evolution rates. For both straw types, Zn had a synergic effect with U, but an antagonistic effect with the other N sources as determined by the total CO2 produced. The MUZ treatment showed the highest decomposition rate and cumulative CO2 concentration （1 120.29 mg/pot）, whereas the WACZ treatment had the lowest cumulative CO2 concentration （1 040.57 mg/pot）. The addition of NH4Cl resulted in the highest total organic carbon （TOC） concentration （11.59 mg kg-1）. The incorporation of wheat straw resulted in higher microbial biomass accumulation in soils relative to that of the maize straw application. The results demonstrate that mineral N sources can affect the ability of microorganisms to decompose straw, as well as the soil carbon concentrations.展开更多
In order to reduce the impact of eutrophication caused by agricultural residues （i.e., excess nitrate） in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic ...In order to reduce the impact of eutrophication caused by agricultural residues （i.e., excess nitrate） in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic sorbent using wheat straw. Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The results indicate that the yield of the prepared anionic sorbent, the total exchange capacity, and the maximum adsorption capacity were 350%, 2.57 mEq/g, and 2.08 mmol/g, respectively. The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation. When multiple anions （SO4^2-, H2PO4^-, NO3^-, and NO2^-） were present, the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode; however, the capacity of nitrate adsorption was reduced by 50%. In alkaline solutions, about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent. The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.展开更多
To accelerate the decomposition of wheat straw directly returned to soil, we constructed a microbial system （ADS-3） from agricultural soil containing rotting straw residues using a 40-wk limited cultivation. To asse...To accelerate the decomposition of wheat straw directly returned to soil, we constructed a microbial system （ADS-3） from agricultural soil containing rotting straw residues using a 40-wk limited cultivation. To assess its potential use for accelerating straw decomposing, the decomposing characteristics and the microbial composition of ADS-3 were analyzed. The results indicated that it could degrade wheat straw and filter paper by 63.8 and 80%, respectively, during 15 d of incubation. Straw hemicellulose degraded dramatically 51.2% during the first 3 d, decreasing up to 73.7% by the end of incubation. Cellulose showed sustained degradation reaching 53.3% in 15 d. Peak values of xylanase and cellulase activities appeared at 3 and 11 d, with 1.32 and 0.15 U mL-1, respectively. Estimated pH averaged 6.4-7.6 during the degradation process, which approximated acidity and alkalinity of normal soils. The microbial composition of ADS-3 was stable based on denaturing gradient gel electrophoresis （DGGE） analysis. By using bacterial 16S rRNA and fungal 26S rRNA gene clone library analysis, 20 bacterial clones and 7 fungal clones were detected. Closest identified relatives of bacteria represented by Bacillus fusiformis, Cytophaga sp., uncultured Clostridiales bacterium, Ruminobacillus xylanolyticum, Clostridium hydroxybenzoicum, and uncultured proteobacterium and the fungi were mainly identified as related to Pichia sp. and uncultured fungus.展开更多
Pot experiments were carried out to study the effect of incorporation of wheat straw and/ or urea into soil on biomass nitrogen and mineral nitrogen and its relation to the growth and yield of rice. The combined appli...Pot experiments were carried out to study the effect of incorporation of wheat straw and/ or urea into soil on biomass nitrogen and mineral nitrogen and its relation to the growth and yield of rice. The combined application of wheat straw and urea increased much more biomass nitrogen in soil than the application of wheat straw or urea alone and consequently increased the immobilization of urea nitrogen added and reduced the loss of urea nitrogen. An adequate nitrogen-supplying process to rice plant could be obtained if C / N ratio of the material added was about 20. The three yield components of rice were affected significantly by the status of nitrogen supplying. More than 30mg N / kg soil of mineral nitrogen at effective tillering stage, panicle initiation stage and filling stage should be maintained in order to get high rice yield, though the criteria varied with the different experimental conditions.展开更多
A study was conducted to test wettability changes of the wheat straw treated with different methods for the preparation of wheat straw particle board. The wheat straws were separately sprayed with two chemicals （0.6%...A study was conducted to test wettability changes of the wheat straw treated with different methods for the preparation of wheat straw particle board. The wheat straws were separately sprayed with two chemicals （0.6% NaOH, 0.3% H2O2） and three enzymes （lipase, xylanase, cellulase）. The contact angle between water and the surface of wheat straw was measured and the spreading-penetration parameters （K-values） were also calculated with wetting model. The surfaces of treated wheat straw and control sample were scanned by means of Micro-FTIR, and their peaks arrangements were analyzed. The surface morphologies of treated wheat straw and control sample were also observed by SEM. Chemical etching was found on the exterior surfaces of the straws treated separately with 0.6% NaOH and 0.3% H2O2; furthermore, the spreading-penetration parameters （K-values） of the distilled water on the exterior surfaces of the treated wheat straw along the grain were higher than that of control. The wettability of exterior surfaces of the wheat straws treated separately with lipase, xylanase and cellulose were improved after treating for seven days, and among the three enzymes treatments, the lipase treatment showed best result. The lipase treatment and NaOH treatment were determined as better methods for improving the wettability of wheat straw surfaces. However, in the economic aspect, NaOH treatment was more practical and easier in the pretreatment for the manufacture of straw particle board.展开更多
We investigated the hydration behavior and some physical/mechanical properties of cement-bonded particleboard （CBPB） containing particles of wheat straw and poplar wood at various usage ratios and bonded with Portla...We investigated the hydration behavior and some physical/mechanical properties of cement-bonded particleboard （CBPB） containing particles of wheat straw and poplar wood at various usage ratios and bonded with Portland cement mixed with different levels of inorganic additives. We determined the setting time and compression strength of cement pastes containing different additives and particles, and studied the effects of these additives and particles on thickness swelling, internal bond strength and modulus of rupture of CBPB by using RSM （Response Surface Methodology）. The mathematical model equations （second-order response functions） were derived to optimize properties of CBPB by computer simulation programming. Predicted values were in agreement with experimental values （R2 values of 0.93, 0.96 and 0.96 for TS, IB and MOR, respectively）. RSM can be efficiently applied to model panel properties. The variables can affect the properties of panels. The cement composites with bending strength 〉 12.5 MPa and internal bond strength 〉 0.28 MPa can be made by using wheat straw as a reinforcing material. Straw particle usage up to 11.5% in the mixture satisfies the minimum requirements of International Standard, EN 312 （2003） for IB and MOR. The dose of 4.95% calcium chloride, by weight of cement, can improve mechanical properties of the panels at the minimum requirement of EN 312. By increasing straw content from 0 to 30%, TS was reduced by increasing straw particle usage up to 1.5% and with 5.54% calcium chloride in the mixture, TS satisfied the EN 312 standard.展开更多
The object of this study was to determine the effect of cellulase and lactic acid bacteria (LAB) on fermentation quality and chemical composition of wheat straw silage. Silages were prepared using a small-scale fermen...The object of this study was to determine the effect of cellulase and lactic acid bacteria (LAB) on fermentation quality and chemical composition of wheat straw silage. Silages were prepared using a small-scale fermentation system and the moisture level was adjusted to 60% of fresh matter (FM) with deionized water. Treatments were designed as: control silage without additives, LAB inoculant Lactobacillus casei Z3-1 (1.0 × 106 cfu·g-1 of FM), commercial inoculant L. plantarum FG 1 (1.0 × 106 cfu·g-1 of FM), Z3-1 + cellulase and FG 1 + cellulase. The neutral detergent fiber (NDF), acid detergent fiber (ADF) and crude protein (CP) contents of the wheat straw prior to ensiling were 76.93%, 48.52% and 4.63% of dry matter (DM), respectively. After 30 days of fermentation, the silages treated with LAB and LAB + cellulase had a lower (P < 0.05) pH and higher (P < 0.05) lactic acid content than the control, and the coliform bacteria, yeast and mold were inhibited at the early stage of fermentation. Besides, silages treated with cellulase had lower (P < 0.05) values of ADF and NDF than the control. The results confirmed that the addition of cellulase and LAB contributed to improving the fermentation quality of wheat straw silage.展开更多
Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide （KOH） to decrease digestion time and enhance biomethane production and fertility value. KOH concentrations o...Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide （KOH） to decrease digestion time and enhance biomethane production and fertility value. KOH concentrations of 1% （KI）, 3% （[（2）, 6% （K3） and 9% （l（4） were tested for wheat straw pretreatment at ambient temperature with a C：N ratio of 25：1.86% of total solids （TS）, 89% of volatile solids （VS） and 22% of lignocellulose, cellulose and hemi- cellulose （LCH） （22%） were decomposed effectively with the wheat straw pretreated by 6% KOH. Enhanced bio- gas production and cumulative biomethane yield of 258 ml. （g VS）-1 were obtained increased by 45% and 41% respectively, compared with untreated wheat straw. Pretreated wheat straw digestion also yielded a digestate with higher fertilizer values potassium （l 38%）, calcium （22%） and magnesium （16%）. These results show that TS, VS and LCH can be effectively removed from wheat straw pretreated with KOH, improving biodegradability biomethane production and fertilizer value.展开更多
The effect of long-term straw return on crop yield, soil potassium（K） content, soil organic matter, and crop response to K from both straw and chemical K fertilizer（K_2SO_4） were investigated in a fixed site field...The effect of long-term straw return on crop yield, soil potassium（K） content, soil organic matter, and crop response to K from both straw and chemical K fertilizer（K_2SO_4） were investigated in a fixed site field experiment for winter wheat-summer maize rotation in 6 years for 12 seasons. The field experiment was located in northern part of North China Plain with a sandy soil in relatively low yield potential. Two factors, straw return and chemical K fertilizer, were studied with two levels in each factor. Field split design was employed, with two straw treatments, full straw return of previous crop（St） and no straw return, in main plots, and two chemical K fertilizer treatments, 0 and 60 kg K2 O ha^（–1）, as sub-plots. The results showed that straw return significantly increased yields of winter wheat and summer maize by 16.5 and 13.2% in average, respectively, and the positive effect of straw return to crop yield showed more effective in lower yield season. Straw return significantly increased K absorption by the crops, with significant increase in straw part. In treatment with straw return, the K content in crop straw increased by 15.9 and 21.8% in wheat and maize, respectively, compared with no straw return treatment. But, straw return had little effect on K content in grain of the crops. Straw return had significant influences on total K uptake by wheat and maize plants, with an increase of 32.7 and 30.9%, respectively. There was a significant correlation between crop yield and K uptake by the plant. To produce 100 kg grain, the wheat and maize plants absorbed 3.26 and 2.24 kg K2 O, respectively. The contents of soil available K and soil organic matter were significantly affected by the straw return with an increase of 6.07 and 23.0%, respectively, compared to no straw return treatment. K_2SO_4 application in rate of 60 kg K2 O ha^（–1） showed no significant effect on wheat and maize yield, K content in crop straw, total K uptake by the crops, soil available K content, and soil organic matter. The apparent K utilization rate（percentage of applied K absorbed by the crop in the season） showed difference for wheat and maize with different K sources. In wheat season, the K utilization rate from K_2SO_4 was higher than that from straw, while in maize season, the K utilization rate from straw was higher than that from chemical fertilizer. In the whole wheat-maize rotation system, the K absorption efficiency by the two crops from straw was higher than that from K_2SO_4.展开更多
The microbial community structures in an integrated two-phase anaerobic reactor（ITPAR）were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at t...The microbial community structures in an integrated two-phase anaerobic reactor（ITPAR）were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at the top and a 50 L conventional upflow methanogenic unit at the bottom, with a recirculation connected to the two units. The reactor had been operated for 21 stages to co-digest fruit/vegetable wastes and wheat straw, which showed a very good biogas production and decomposition of cellulosic materials. The results showed that many kinds of cellulose and glycan decomposition bacteria related with Bacteroidales,Clostridiales and Syntrophobacterales were dominated in the reactor, with more bacteria community diversities in the acidogenic unit. The methanogens were mostly related with Methanosaeta, Methanosarcina, Methanoculleus, Methanospirillum and Methanobacterium; the predominating genus Methanosaeta, accounting for 40.5%, 54.2%, 73.6% and 78.7% in four samples from top to bottom, indicated a major methanogenesis pathway by acetoclastic methanogenesis in the methanogenic unit. The beta diversity indexes illustrated a more similar distribution of bacterial communities than that of methanogens between acidogenic unit and methanogenic unit. The differentiation of methanogenic community composition in two phases, as well as pH values and volatile fatty acid（VFA） concentrations confirmed the phase separation of the ITPAR. Overall, the results of this study demonstrated that the special designing of ITPAR maintained a sufficient number of methanogens, more diverse communities and stronger syntrophic associations among microorganisms, which made two phase anaerobic digestion of cellulosic materials more efficient.展开更多
Effect of application of K fertilizer and wheat straw to soil on crop yield and status of soil K in the plough layer under different planting systems was studied.The experiments on long-term application of K fertilize...Effect of application of K fertilizer and wheat straw to soil on crop yield and status of soil K in the plough layer under different planting systems was studied.The experiments on long-term application of K fertilizer and wheat straw to soil in Hebei fluvo aquic soil and Shanxi brown soil in northern China were begun in 1992.The results showed that K fertilizer and straw could improve the yields of wheat and maize with the order of NPK+St〉NPK〉NP+St〉NP,and treatment of K fertilizer made a significant difference to NP,and the efficiency of K fertilizer in maize was higher than in wheat under rotation system of Hebei.In contrast with Shanxi,the wastage of soil potassium was a more serious issue in the rotation system in Hebei,only treatment of NPK+St showed a surplus of potassium and the others showed a wane.K fertilizer and straw could improve the content of water-soluble K,nonspecifically adsorbed K,non-exchangeable K,mineral K,and total K in contrast to NP;however,K fertilizer and straw reduce the proportion of mineral K and improve proportion of other forms of potassium in the two locating sites.Compared with the beginning of orientation,temporal variability character of soil K content and proportion showed a difference between the two soil types;furthermore,there was a decrease in the content of mineral K and total K simultaneously in the two locating sites.As a whole,the effect of K fertilizer applied to soil directly excelled to wheat straw to soil.Wheat straw to soil was an effective measure to complement potassium to increase crop yield and retard the decrease of soil K.展开更多
基金Supported by National Natural Science Foundation(70741032)~~
文摘Based on researches of the crop potential productivity,the potential productivity of light,temperature,water and land from wheat in China were calculated respectively,and converted into the potential productivity of wheat straw according to the coefficient of grain-straw ratio of wheat.Furthermore,based on the wheat planting area in 2006,the potential yield of wheat straw fiber in China was estimated.The results showed that the potential yield of wheat straw fiber in China could reach 94.91 million ton,which could provide evidence for the further potential analysis of bio-ethanol.
基金Supported by National Science and Technology Support Program(2006BAD05B06-04)~~
文摘[Objective]The aim was to study the effects of regulation of C/N ratio wheat straw application on tobacco nitrogen,phosphorus and potassium uptake. [Method]Effects of regulation C/N ratio wheat straw application on the flue-cured tobacco yield,output value,nitrogen,phosphorus and potassium content and cumulative uptake of the upper,middle and bottom leaf were studied by using the field plot experiments at Banqiao town,Qujing city,Yunnan Province during the 2008-2009 summer growing seasons. [Result]The results showed that the application of wheat straw alone or after C/N regulation,could significantly increase tobacco production,potassium content,the potassium and nitrogen accumulation amount of leaf,and was more conducive to the potassium uptake of tobacco leaf with wheat straw application after C/N regulation. Compared with non-straw application,the yield of tobacco increased by 6.59%,3.58%,5.98%,8.80% with application of wheat straw alone,wheat straw and vetch,wheat straw and oilseed cake,wheat straw and urea nitrogen,the potassium content in tobacco leaf increased by 3.85%,7.76%,8.82%,11.21%,respectively,the total potassium cumulative amount of leaf increased by 10.71%,11.62%,15.32% ,21.01% and the total nitrogen cumulative amount increased by 9.76%,1.22%,8.14%,14.00%. However,the differences of tobacco leaf nitrogen content among the different treatments were not significant,the phosphorus uptake of tobacco leaf decreased. [Conclusion]application of high C/N ratio wheat straw in flue-cured tobacco production,which should be concerned not only to adjust C/N ratio by adding nitrogen,but also considering additional phosphorus application.
文摘In order to study the effect of rice straw returning and seeding patterns on seedling emergence and grain yield, field experiment was conducted to investi- gate the effects of straw mechanized returning and different seeding patterns on e- mergence rate, emergence uniformity and yield traits of wheat after rice. The results were as follows： in rice straw removal treatments, the emergence rate of mechani- cal seeding in drill was lower than that of mechanical uniform planting and manual broadcast sowing, which were 51.84%, 90.89% and 88.87%, respectively; the emer- gence uniformity of manual broadcast sowing was inferior to mechanical seeding in drill and mechanical uniform planting, which were 0.49, 0.26 and 0.23, respectively. As for the treatments with rice straw returning to the field, the emergence rate and emergence uniformity all decreased in the three seeding patterns, of which mechan- ical seeding in drill dropped markedly with emergence rate decreased by 36.54%. The emergence rate and emergence uniformity affected grain yield by affecting pan- icle, grains per spike and 1 000-grain weight. The grain yield for the treatment with rice straw removal was 6 091.34 kg/hm2, while that with rice straw returning to field was 6 476.20 kg/hm2, and both were higher than the yields of the other two seed- ing patterns. Therefore, mechanical uniform planting was？recommended for its higher emergence rate, better emergence uniformity, which was conductive to increase grain yield in wheat after rice production with rice straw returning to field.
基金Supported by Jiangsu Agricultural Science and Technology Innovation Fund(CX(12)3034)Jiangsu Three Agricultural Innovation Project(SXGC[2014]299)National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2014BAD11B02)~~
文摘Objective] The aim was to study the effects of cotton straw extract on wheat root growth and define the al elopathic effect of cotton straw on wheat root. [Method] A sand culture experiment was conducted under different cotton straw ex-tract levels （0%, 1.0%, 2.0%, 4.0%, 8.0% and 10.0%）, and the morphology and physiological activity of wheat （Yangmai 13） root were studied. [Result] The cotton straw extract inhibited the elongation of wheat roots, but increased the root diame-ter, resulting in the decreased root surface area and volume; The extract treatments induced the increase of root reactive oxygen species （ROS） level, which led to an increased root membrane lipid peroxidation, thereby reducing the root vigor and in-hibiting the root water uptake and formation of biomass; With the increase of con-centration of cotton straw extract, the total phenolic acid content in the extract in-creased continuously, and the total phenolic acid content was closely related to the morphogenesis and physiological activity of wheat root. [Conclusion] The cotton straw extract inhibited the morphogenesis and physiological activity of wheat root through affecting the root ROS level, and the total phenolic content was one of the main limiting factors.
基金Supported by Science and Technology Support Program of Sichuan Province(2014NZ0044)~~
文摘[Objective] The aim was to investigate the application effect of swine manure-straw returning and to determine the best mode. [Method] A field experiment under rice and wheat rotation with different swine manure-straw treatments was con- ducted to study the growth characters and output of rice and wheat, calculate the economic benefit and carbon dioxide emission reduction, and analyze the best mode of swine manure applying-straw returning. [Result] The swine manure-straw returning was conducive to the growth of crop, the highest outputs of rice and wheat were on the treatment of ＂30% swine manure and 20% straw and 50% chemical fertiliz- er＂, they were 7 874.57 and 6 427.00 kg/hm^2, and saved cost about 5 146.35 Yuan/hm^2, increased input 5 312.56 and 3 931.93 Yuan/hm^2, the greenhouse gas e- mission reduction was 1.30 t/hm^2 （calculated according to carbon dioxide on a dry basis）. [Conclusion] The treatment of ＂30% swine manure and 20% straw and 50% chemical fertilizer＂ was the best mode of swine manure-straw returning.
基金Supported by the Fund for Independent Innovation of Agricultural Science and Technology in Jiangsu Province[CX(12)1002]National Science and Technology Project(2013BAD07B09)Major Special Project of National Water Pollution Control and Governance(2012ZX07101-004)~~
文摘A case study of Jiangsu Province was conducted using questionnaires and field survey to explore the status quo of the collection and utilization of rice and wheat straw of the province. Problems in collecting the straw were analyzed taking into account meteorological data of the rice and wheat harvesting seasons in the region. Results show：（1） Currently, the main handling way of rice and wheat straw was directly returning to field. The peasant households of straw returning from investigated townships A and B respectively occupied 22.01% and 28.75% of investigation households, and both of the two townships had a considerable portion of the straw wasted or improperly disposed. In township B, over 50% of the farmer households surveyed failed to make sure of any of the straw, and as high as over55% of the straw was discarded or burnt.（2） During the rice and wheat harvesting seasons, the ten-day precipitation was among 7.21-87.28 mm, and the ten-day precipitation days were among 1.53-5.00 d. Such weather not only affected timely harvesting of rice and wheat, but also seriously impeded baling, transportation and storage of straw.（3） As the crops must be harvested in a relatively short and concentrated time period, large volumes of straw were turned out within a few days.Moreover, harvesting of the first crop often coincided with sowing, leaving little time available for straw collection.（4） Straw collection was very low in economic benefit.A farmer can only get 60-90 RMB per day from straw collection and transportation,which was much lower than what they can get by working as migrant workers in the city.（5） Machines designed for straw collection were rare and those now used in the operation were low in efficiency and needed to be improved technically,which directly affected the efficiency of straw collection. The above-listed findings indicates that time shortage, negative weather condition, low benefit and low mechanization level were major factors affecting straw collection. To solve the problems,the following proposals were brought forth, that is, improving the economic benefit of straw collection as a driving force, accelerating the research and development of rice and wheat sheaf-binding reaping machine, and setting up a long-term operational mechanism for straw recovery, in the hope that this study may provide some useful ideas to help solve the problems.
基金Supported by the Project of Returned Overseas of Harbin Science and Technology Bureau(RC2010LX002005)the Project of Science and Technology Department of Heilongjiang Province(LC07C27)~~
文摘[Objective] The aim was to improve the adhesive bonding property of wheat straw surface to prepare wheat straw particleboard of soy protein isolate （SPI） adhesive through chemical and enzyme treatments. [Method] Evaluation and analysis were made on wettability of wheat straws in the control group and treated groups （chemical and enzyme treatments） by means of measurement of contact angle and calculation of spreading-penetration parameters （K）. In addition, we made analysis on surface elements through X-ray photoelectron spectroscopy （XPS）. [Result] The re- sults showed that K value of straw treated with sodium hydroxide, hydrogen peroxide and lipase increased by 58.0%, 48.7% and 83.2% compared to that of control group, respectively. The XPS analysis indicated that rapid decrease of silicon content and destruction of wax layer greatly contributed to wettability improvement of wheat straw surface. [Conclusion] The chemical and lipase treatments of wheat straw provided technical support for manufacture of wheat straw particle boand.
基金supported by the National Key Research and Development Program of China(2016YFD0300400)the National Basic Research Program of China(973 Program,2015CB150404)+4 种基金the Special Fund for Agroscientific Research in Public Interest of China(201203100)the National Key Technologies R&D Program of China during the 12th Five-year Plan period(2012BAD04B05)the Project of Shandong Province Higher Educational Science and Technology,China(J14LF12)the Shandong Province Mount Tai Industrial Talents Program,Chinathe Shandong Province Key Agricultural Project for Application Technology Innovation,China
文摘Straw return is an important management tool for tackling and promoting soil nutrient conservation and improving crop yield in Huang-Huai-Hai Plain, China. Although the incorporation of maize straw with deep plowing and rotary tillage practices are widespread in the region, only few studies have focused on rotation tillage. To determine the effects of maize straw return on the nitrogen （N） efficiency and grain yield of winter wheat （Triticum aestivum L.）, we conducted experiments in this region for 3 years. Five treatments were tested： （i） rotary tillage without straw return （RT）; （ii） deep plowing tillage without straw return （DT）; （iii） rotary tillage with total straw return （RS）; （iv） deep plowing tillage with total straw return （DS）; （v） rotary tillage of 2 years and deep plowing tillage in the 3rd year with total straw return （TS）. Treatments with straw return increased kernels no. ear-1, thousand-kernel weight （TKW）, grain yields, ratio of dry matter accumulation post-anthesis, and nitrogen （N） efficiency whereas reduced the ears no. ha-1 in the 2011-2012 and 2012-2013 growing seasons. Compared with the rotary tillage, deep plowing tillage significantly increased the grain yield, yield components, total dry matter accumulation, and N efficiency in 2013-2014. RS had significantly higher straw N distribution, soil inorganic nitrogen content, and soil enzymes activities in the 0-10 cm soil layer compared with the DS and TS. However, significantly lower values were ob- served in the 10-20 and 20-30 cm soil layers. TS obtained approximately equal grain yield as DS, and it also reduced the resource costs. Therefore, we conclude that TS is the most economical method for increasing grain yield and N efficiency of winter wheat in Huang-Huai-Hai Plain.
基金financially supported by the Key Technologies R&D Program of China during the 12th FiveYear Plan period (2011BAD16B08, 2012BAD04B06 and 2013BAD07B05)
文摘In northern China, the soil-born diseases of wheat have been getting more and more serious under a new farming system that returns maize straw to the field. In order to investigate the allelopathy of the decomposed maize straw products on three soil-born diseases of wheat, culture dish and pot experiments were conducted and the compounds in the products were identified by gas chromatography-mass spectrometry （GC-MS）. Culture dish experiments showed that the mycelial growth, sclerotia formation amount and total weight of Rhizoctonia cerealis were promoted at concentrations of 0.03, 0.06 and 0.12 g mL-1 and inhibited at concentration of 0.48 g mL-1 of the decomposed products. No significant effects were found of the product concentrations on average weight of the sclerotia. Mycelial growth of Gaeumannomyces graminis was promoted at almost all concentrations except the highest one. Mycelial growth and spore germination of Bipolaris sorokiniana were significantly inhibited by all concentrations of the decomposed products, with enhanced inhibition effects along with the increased concentrations. The length, number and dry weight of roots together with the root superoxide dismutase activity were promoted by the lowest concentration （0.03 g mL-1）, with a synthetic effect index of 0.012, and inhibited by other concentrations. The ion leakage of roots was increased and the root peroxidase activity of roots was lowered by all the treatments. Pot experiments revealed that occurrence of the sharp eyespot was reduced by 0.03 and 0.06 g mL-1 of decomposed products after irrigation. However, the incidence rates and disease indexes were significantly increased by 0.12, 0.24 and 0.48 g mL-1 of decomposed products. The results indicated that incidence rates and disease indexes of the take-all were significantly promoted after being irrigated with the decomposed products, while occurrences of the common rot didn＇t change, significantly. GC-MS results showed that the compounds of the decomposed products included organic acids, esters, hydrocarbons, amides and aldehydes, with the proportions 25.26, 24.01, 17.22, 14.39 and 7.73%, respectively. Further analysis investigated that the allelochemicals identified in straw decomposed products contained p-hydroxybenzoic acid （9.21%）, dibutyl phthalate （6.94%）, 3-phenyl-2-acrylic （5.06%）, 4-hydroxy-3,5-dimethoxybenzoic acid （2.26%）, hexanoic acid （1.73%）, 8-octadecenoic acid （1.06%）, 3-（4-hydroxy-3-methoxy-phenyl）-2-propenoic acid （1.04%）, 4-hydroxy-3-methoxy-benzoic acid （0.94%） and salicylic acid （0.94%）.
基金supported by the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2012BAD14B11)the National Natural Science Foundation of China (41371288, 31071863)the Fundamental Research Funds for Northwest A&F University, China (QN2011074)
文摘The incorporation of straw in cultivated ifelds can potentially improve soil quality and crop yield. However, the presence of recalcitrant carbon compounds in straw slow its decomposition rate. The objective of this study was to determine the effects of different nitrogen sources, with and without the application of zinc, on straw decomposition and soil quality. Soils were treated with three different nitrogen sources, with and without zinc： urea （CO（NH2）2）, ammonium sulfate （（NH4）2SO4）, and ammonium chloride （NH4Cl）. The combined treatments were as follows：maize （M） and wheat （W） straw incorporated into urea-, ammonium sulfate-, or ammonium chloride-treated soil （U, S, and C, respectively） with and without zinc （Z） （MU, MUZ, WU, WUZ;MS, MSZ, WS, WSZ;MC, MCZ, WC, WCZ, respectively）;straw with zinc only （MZ, WZ）;straw with untreated soil （MS, WS）;and soil-only or control conditions （NT）. The experiment consisted of 17 treatments with four replications. Each pot contained 150 g soil and 1.125 g straw, had a moisture content of 80%of the ifeld capacity, and was incubated for 53 days at 25°C. The rates of CO2-C emission, cumulative CO2-C evolution, total CO2 production in the soils of different treatments were measured to infer decomposition rates. The total organic carbon （TOC）, labile organic carbon （LOC）, and soil microbial biomass in the soils of different treatments were measured to infer soil quality. All results were signiifcantly different （P〈0.05） with the exception of the labile organic carbon （LOC）. The maize and wheat straw showed different patterns in CO2 evolution rates. For both straw types, Zn had a synergic effect with U, but an antagonistic effect with the other N sources as determined by the total CO2 produced. The MUZ treatment showed the highest decomposition rate and cumulative CO2 concentration （1 120.29 mg/pot）, whereas the WACZ treatment had the lowest cumulative CO2 concentration （1 040.57 mg/pot）. The addition of NH4Cl resulted in the highest total organic carbon （TOC） concentration （11.59 mg kg-1）. The incorporation of wheat straw resulted in higher microbial biomass accumulation in soils relative to that of the maize straw application. The results demonstrate that mineral N sources can affect the ability of microorganisms to decompose straw, as well as the soil carbon concentrations.
基金Project supported by the Key Science Project of Environmental Protection Foundation of Shandong Government(No.(2006)005).
文摘In order to reduce the impact of eutrophication caused by agricultural residues （i.e., excess nitrate） in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic sorbent using wheat straw. Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The results indicate that the yield of the prepared anionic sorbent, the total exchange capacity, and the maximum adsorption capacity were 350%, 2.57 mEq/g, and 2.08 mmol/g, respectively. The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation. When multiple anions （SO4^2-, H2PO4^-, NO3^-, and NO2^-） were present, the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode; however, the capacity of nitrate adsorption was reduced by 50%. In alkaline solutions, about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent. The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.
基金supported by the National Key Technology R&D Program of China (2008BADC4B01 and 2008BADC4B17)the National Special Research Fund for Non-Profit Sector, China (200803033)
文摘To accelerate the decomposition of wheat straw directly returned to soil, we constructed a microbial system （ADS-3） from agricultural soil containing rotting straw residues using a 40-wk limited cultivation. To assess its potential use for accelerating straw decomposing, the decomposing characteristics and the microbial composition of ADS-3 were analyzed. The results indicated that it could degrade wheat straw and filter paper by 63.8 and 80%, respectively, during 15 d of incubation. Straw hemicellulose degraded dramatically 51.2% during the first 3 d, decreasing up to 73.7% by the end of incubation. Cellulose showed sustained degradation reaching 53.3% in 15 d. Peak values of xylanase and cellulase activities appeared at 3 and 11 d, with 1.32 and 0.15 U mL-1, respectively. Estimated pH averaged 6.4-7.6 during the degradation process, which approximated acidity and alkalinity of normal soils. The microbial composition of ADS-3 was stable based on denaturing gradient gel electrophoresis （DGGE） analysis. By using bacterial 16S rRNA and fungal 26S rRNA gene clone library analysis, 20 bacterial clones and 7 fungal clones were detected. Closest identified relatives of bacteria represented by Bacillus fusiformis, Cytophaga sp., uncultured Clostridiales bacterium, Ruminobacillus xylanolyticum, Clostridium hydroxybenzoicum, and uncultured proteobacterium and the fungi were mainly identified as related to Pichia sp. and uncultured fungus.
文摘Pot experiments were carried out to study the effect of incorporation of wheat straw and/ or urea into soil on biomass nitrogen and mineral nitrogen and its relation to the growth and yield of rice. The combined application of wheat straw and urea increased much more biomass nitrogen in soil than the application of wheat straw or urea alone and consequently increased the immobilization of urea nitrogen added and reduced the loss of urea nitrogen. An adequate nitrogen-supplying process to rice plant could be obtained if C / N ratio of the material added was about 20. The three yield components of rice were affected significantly by the status of nitrogen supplying. More than 30mg N / kg soil of mineral nitrogen at effective tillering stage, panicle initiation stage and filling stage should be maintained in order to get high rice yield, though the criteria varied with the different experimental conditions.
基金funded by theScientific Research Foundation of the Bureau of Science and Technologyof Heilongjiang Province (LC07C27)
文摘A study was conducted to test wettability changes of the wheat straw treated with different methods for the preparation of wheat straw particle board. The wheat straws were separately sprayed with two chemicals （0.6% NaOH, 0.3% H2O2） and three enzymes （lipase, xylanase, cellulase）. The contact angle between water and the surface of wheat straw was measured and the spreading-penetration parameters （K-values） were also calculated with wetting model. The surfaces of treated wheat straw and control sample were scanned by means of Micro-FTIR, and their peaks arrangements were analyzed. The surface morphologies of treated wheat straw and control sample were also observed by SEM. Chemical etching was found on the exterior surfaces of the straws treated separately with 0.6% NaOH and 0.3% H2O2; furthermore, the spreading-penetration parameters （K-values） of the distilled water on the exterior surfaces of the treated wheat straw along the grain were higher than that of control. The wettability of exterior surfaces of the wheat straws treated separately with lipase, xylanase and cellulose were improved after treating for seven days, and among the three enzymes treatments, the lipase treatment showed best result. The lipase treatment and NaOH treatment were determined as better methods for improving the wettability of wheat straw surfaces. However, in the economic aspect, NaOH treatment was more practical and easier in the pretreatment for the manufacture of straw particle board.
基金supported by Department of Wood and Paper Science and Technology,University of Zabol
文摘We investigated the hydration behavior and some physical/mechanical properties of cement-bonded particleboard （CBPB） containing particles of wheat straw and poplar wood at various usage ratios and bonded with Portland cement mixed with different levels of inorganic additives. We determined the setting time and compression strength of cement pastes containing different additives and particles, and studied the effects of these additives and particles on thickness swelling, internal bond strength and modulus of rupture of CBPB by using RSM （Response Surface Methodology）. The mathematical model equations （second-order response functions） were derived to optimize properties of CBPB by computer simulation programming. Predicted values were in agreement with experimental values （R2 values of 0.93, 0.96 and 0.96 for TS, IB and MOR, respectively）. RSM can be efficiently applied to model panel properties. The variables can affect the properties of panels. The cement composites with bending strength 〉 12.5 MPa and internal bond strength 〉 0.28 MPa can be made by using wheat straw as a reinforcing material. Straw particle usage up to 11.5% in the mixture satisfies the minimum requirements of International Standard, EN 312 （2003） for IB and MOR. The dose of 4.95% calcium chloride, by weight of cement, can improve mechanical properties of the panels at the minimum requirement of EN 312. By increasing straw content from 0 to 30%, TS was reduced by increasing straw particle usage up to 1.5% and with 5.54% calcium chloride in the mixture, TS satisfied the EN 312 standard.
文摘The object of this study was to determine the effect of cellulase and lactic acid bacteria (LAB) on fermentation quality and chemical composition of wheat straw silage. Silages were prepared using a small-scale fermentation system and the moisture level was adjusted to 60% of fresh matter (FM) with deionized water. Treatments were designed as: control silage without additives, LAB inoculant Lactobacillus casei Z3-1 (1.0 × 106 cfu·g-1 of FM), commercial inoculant L. plantarum FG 1 (1.0 × 106 cfu·g-1 of FM), Z3-1 + cellulase and FG 1 + cellulase. The neutral detergent fiber (NDF), acid detergent fiber (ADF) and crude protein (CP) contents of the wheat straw prior to ensiling were 76.93%, 48.52% and 4.63% of dry matter (DM), respectively. After 30 days of fermentation, the silages treated with LAB and LAB + cellulase had a lower (P < 0.05) pH and higher (P < 0.05) lactic acid content than the control, and the coliform bacteria, yeast and mold were inhibited at the early stage of fermentation. Besides, silages treated with cellulase had lower (P < 0.05) values of ADF and NDF than the control. The results confirmed that the addition of cellulase and LAB contributed to improving the fermentation quality of wheat straw silage.
基金Supported by Specialized Research Fund for the Doctoral Program of Higer Education(20120010110004)the Natural Science Foundation of Beijing(8142030)
文摘Wheat straw biodegradability during anaerobic digestion was improved by treatment with potassium hydroxide （KOH） to decrease digestion time and enhance biomethane production and fertility value. KOH concentrations of 1% （KI）, 3% （[（2）, 6% （K3） and 9% （l（4） were tested for wheat straw pretreatment at ambient temperature with a C：N ratio of 25：1.86% of total solids （TS）, 89% of volatile solids （VS） and 22% of lignocellulose, cellulose and hemi- cellulose （LCH） （22%） were decomposed effectively with the wheat straw pretreated by 6% KOH. Enhanced bio- gas production and cumulative biomethane yield of 258 ml. （g VS）-1 were obtained increased by 45% and 41% respectively, compared with untreated wheat straw. Pretreated wheat straw digestion also yielded a digestate with higher fertilizer values potassium （l 38%）, calcium （22%） and magnesium （16%）. These results show that TS, VS and LCH can be effectively removed from wheat straw pretreated with KOH, improving biodegradability biomethane production and fertilizer value.
基金supported by the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2015BAD23B02)
文摘The effect of long-term straw return on crop yield, soil potassium（K） content, soil organic matter, and crop response to K from both straw and chemical K fertilizer（K_2SO_4） were investigated in a fixed site field experiment for winter wheat-summer maize rotation in 6 years for 12 seasons. The field experiment was located in northern part of North China Plain with a sandy soil in relatively low yield potential. Two factors, straw return and chemical K fertilizer, were studied with two levels in each factor. Field split design was employed, with two straw treatments, full straw return of previous crop（St） and no straw return, in main plots, and two chemical K fertilizer treatments, 0 and 60 kg K2 O ha^（–1）, as sub-plots. The results showed that straw return significantly increased yields of winter wheat and summer maize by 16.5 and 13.2% in average, respectively, and the positive effect of straw return to crop yield showed more effective in lower yield season. Straw return significantly increased K absorption by the crops, with significant increase in straw part. In treatment with straw return, the K content in crop straw increased by 15.9 and 21.8% in wheat and maize, respectively, compared with no straw return treatment. But, straw return had little effect on K content in grain of the crops. Straw return had significant influences on total K uptake by wheat and maize plants, with an increase of 32.7 and 30.9%, respectively. There was a significant correlation between crop yield and K uptake by the plant. To produce 100 kg grain, the wheat and maize plants absorbed 3.26 and 2.24 kg K2 O, respectively. The contents of soil available K and soil organic matter were significantly affected by the straw return with an increase of 6.07 and 23.0%, respectively, compared to no straw return treatment. K_2SO_4 application in rate of 60 kg K2 O ha^（–1） showed no significant effect on wheat and maize yield, K content in crop straw, total K uptake by the crops, soil available K content, and soil organic matter. The apparent K utilization rate（percentage of applied K absorbed by the crop in the season） showed difference for wheat and maize with different K sources. In wheat season, the K utilization rate from K_2SO_4 was higher than that from straw, while in maize season, the K utilization rate from straw was higher than that from chemical fertilizer. In the whole wheat-maize rotation system, the K absorption efficiency by the two crops from straw was higher than that from K_2SO_4.
基金supported by the Major Science and Technology Programs for Water Pollution Control and Management of China(No.2012ZX07205-001)the National Science and Technology Support Program(No.2008BADC4B18)
文摘The microbial community structures in an integrated two-phase anaerobic reactor（ITPAR）were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at the top and a 50 L conventional upflow methanogenic unit at the bottom, with a recirculation connected to the two units. The reactor had been operated for 21 stages to co-digest fruit/vegetable wastes and wheat straw, which showed a very good biogas production and decomposition of cellulosic materials. The results showed that many kinds of cellulose and glycan decomposition bacteria related with Bacteroidales,Clostridiales and Syntrophobacterales were dominated in the reactor, with more bacteria community diversities in the acidogenic unit. The methanogens were mostly related with Methanosaeta, Methanosarcina, Methanoculleus, Methanospirillum and Methanobacterium; the predominating genus Methanosaeta, accounting for 40.5%, 54.2%, 73.6% and 78.7% in four samples from top to bottom, indicated a major methanogenesis pathway by acetoclastic methanogenesis in the methanogenic unit. The beta diversity indexes illustrated a more similar distribution of bacterial communities than that of methanogens between acidogenic unit and methanogenic unit. The differentiation of methanogenic community composition in two phases, as well as pH values and volatile fatty acid（VFA） concentrations confirmed the phase separation of the ITPAR. Overall, the results of this study demonstrated that the special designing of ITPAR maintained a sufficient number of methanogens, more diverse communities and stronger syntrophic associations among microorganisms, which made two phase anaerobic digestion of cellulosic materials more efficient.
文摘Effect of application of K fertilizer and wheat straw to soil on crop yield and status of soil K in the plough layer under different planting systems was studied.The experiments on long-term application of K fertilizer and wheat straw to soil in Hebei fluvo aquic soil and Shanxi brown soil in northern China were begun in 1992.The results showed that K fertilizer and straw could improve the yields of wheat and maize with the order of NPK+St〉NPK〉NP+St〉NP,and treatment of K fertilizer made a significant difference to NP,and the efficiency of K fertilizer in maize was higher than in wheat under rotation system of Hebei.In contrast with Shanxi,the wastage of soil potassium was a more serious issue in the rotation system in Hebei,only treatment of NPK+St showed a surplus of potassium and the others showed a wane.K fertilizer and straw could improve the content of water-soluble K,nonspecifically adsorbed K,non-exchangeable K,mineral K,and total K in contrast to NP;however,K fertilizer and straw reduce the proportion of mineral K and improve proportion of other forms of potassium in the two locating sites.Compared with the beginning of orientation,temporal variability character of soil K content and proportion showed a difference between the two soil types;furthermore,there was a decrease in the content of mineral K and total K simultaneously in the two locating sites.As a whole,the effect of K fertilizer applied to soil directly excelled to wheat straw to soil.Wheat straw to soil was an effective measure to complement potassium to increase crop yield and retard the decrease of soil K.
