Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer...Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer is a very important water source when growing alfalfa in Southwest Kansas and unfortunately, the water level of the Ogallala Aquifer is shrinking. The objective of this study was to determine the optimum cutting interval that optimizes dry matter yield and nutritive values of alfalfa. Alfalfa was harvested with different cutting intervals, i.e., every 28, 35, 42 and 49 day, which was equivalent of 5, 4, 4, and 3 cuttings per year, respectively in 2013 and 2014. Based on 2-yr total yield, by delaying alfalfa harvest by 21 days, i.e., from every 28th day to 49th day, alfalfa yield increased by 2.25 Mg/ha whereas by 5.58 Mg/ha by delaying cutting intervals from every 28th day to 42nd day. Although harvesting alfalfa every 42nd day had the same cutting frequency as the 35th day treatment (i.e., 4 cuttings per year), the treatment harvesting every 42nd day had significantly higher alfalfa yield than 35th day cutting interval. Alfalfa yield increased by approximately 20% by delaying one week for harvesting alfalfa from 35th to 42nd day interval, based on dry matter yields of 2013 and 2014. As cutting interval increased from every 28th to 49th day, crude protein (CP) content decreased. In contrast to CP, acid detergent fiber and neutral detergent fiber increased as the cutting interval and stage of maturity increased in 2013 and 2014. The results suggest that alfalfa producers in Southwest Kansas possibly could reduce the cutting frequency from 5 to 4 per year. Cutting interval of every 42nd day between harvests appears to be the optimum when considered a dry matter yield and nutritive values in alfalfa.展开更多
Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the performance of alternate wetting and d...Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the performance of alternate wetting and drying furrow irrigation（AWDFI） on crop growth, yield, water use efficiency（WUE）, fruit quality and profitability analysis of tomato. The experiment was laid out in randomized complete block design with six treatments replicated thrice during the dry seasons of 2013-2014 and 2014-2015. Irrigation water was applied through three ways of furrow： AWDFI, fixed wetting and drying furrow irrigation（FWDFI） and traditional（every） furrow irrigation（TFI）. Each irrigation method was divided into two levels： irrigation up to 100 and 80% field capacity（FC）. Results showed that plant biomass（dry matter） and marketable fruit yield of tomato did not differ significantly between the treatments of AWDFI and TFI, but significant difference was observed in AWDFI and in TFI compared to FWDFI at same irrigation level. AWDFI saved irrigation water by 35 to 38% for the irrigation levels up to 80 and 100% FC, compared to the TFI, respectively. AWDFI improved WUE by around 37 to 40% compared to TFI when irrigated with 100 and 80% FC, respectively. Fruit quality（total soluble solids and pulp） was found greater in AWDFI than in TFI. Net return from AWDFI technique was found nearly similar compared to TFI and more than FWDFI. The benefit cost ratio was viewed higher in AWDFI than in TFI and FWDFI by 2.8, 8.7 and 11, 10.4% when irrigation water was applied up to 100 and 80% FC, respectively. Unit production cost was obtained lower in AWDFI compared to TFI and FWDFI. However, AWDFI is a useful water-saving furrow irrigation technique which may resolve as an alternative choice compared with TFI in the areas where available water and supply methods are limited to irrigation.展开更多
To meet the major challenge of increasing rice production to feed a growing population under increasing water scarcity,many water-saving regimes have been introduced in irrigated rice,such as an aerobic rice system,no...To meet the major challenge of increasing rice production to feed a growing population under increasing water scarcity,many water-saving regimes have been introduced in irrigated rice,such as an aerobic rice system,non-flooded mulching cultivation,and alternate wetting and drying(AWD).These regimes could substantially enhance water use efficiency(WUE) by reducing irrigation water.However,such enhancements greatly compromise grain yield.Recent work has shown that moderate AWD,in which photosynthesis is not severely inhibited and plants can rehydrate overnight during the soil drying period,or plants are rewatered at a soil water potential of-10 to-15 k Pa,or midday leaf potential is approximately-0.60 to-0.80 MPa,or the water table is maintained at 10 to 15 cm below the soil surface,could increase not only WUE but also grain yield.Increases in grain yield WUE under moderate AWD are due mainly to reduced redundant vegetative growth;improved canopy structure and root growth;elevated hormonal levels,in particular increases in abscisic acid levels during soil drying and cytokinin levels during rewatering;and enhanced carbon remobilization from vegetative tissues to grain.Moderate AWD could also improve rice quality,including reductions in grain arsenic accumulation,and reduce methane emissions from paddies.Adoption of moderate AWD with an appropriate nitrogen application rate may exert a synergistic effect on grain yield and result in higher WUE and nitrogen use efficiency.Further research is needed to understand root–soil interaction and evaluate the long-term effects of moderate AWD on sustainable agriculture.展开更多
This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency （WUE） under alternate wetting and drying （AWD） irrigation than...This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency （WUE） under alternate wetting and drying （AWD） irrigation than check rice. Two super rice cultivars and two elite check rice cultivars were grown in pots with three soil moisture levels, well watered （WW）, moderate water deficit （MWD） and severe water deficit （SWD）. Two cultivars, each for super rice and check rice, were grown in field with three irrigation regimes, alternate wetting and moderate drying （AWMD）, alternate wetting and severe drying （AWSD） and conventional irrigation （CI）. Compared with that under WW, grain yield was significantly decreased under MWD and SWD treatments, with less reduction for super rice than for check rice. Super rice had higher percentage of productive tillers, deeper root distribution, higher root oxidation activity, and greater aboveground biomass production at mid and late growth stages than check rice, especially under WMD and WSD. Compared with CI,AWMD increased, whereasAWSD decreased grain yield, with more increase or less decrease for super rice than for check rice. Both MWD and SWD treatments and eitherAWMD orAWSD regime significantly increased WUE compared with WW treatment or CI regime, with more increase for super rice than for check rice. The results suggest that super rice has a stronger ability to cope with soil water deficit and holds greater promising to increase both grain yield and WUE by adoption of moderate AWD irrigation.展开更多
Climate change is recognized to increase the frequency and severity of extreme temperature events. At flowering and grain filling stages, risk of high temperature stress （HTS） on rice might increase, and lead to dec...Climate change is recognized to increase the frequency and severity of extreme temperature events. At flowering and grain filling stages, risk of high temperature stress （HTS） on rice might increase, and lead to declining grain yields. A regulated cabinet experiment was carried out to investigate effects of high temperature stress on rice growth at flowering and grain- filling stages. Results showed that no obvious decrease pattern in net photosynthesis appeared along with the temperature rising, but the dry matter allocation in leaf, leaf sheath, culm, and panicle all changed. Dry weight of panicle decreased, and ratio of straw to total above ground crop dry weight increased 6-34% from CK, which might have great effects on carbon cycling and green house gas emission. Grain yield decreased significantly across all treatments on average from 15 to 73%. Occurrence of HTS at flowering stage showed more serious influence on grain yield than at grain filling stage. High temperature stress showed negative effects on harvest index. It might be helpful to provide valuable information for crop simulation models to capture the effects of high temperature stress on rice, and evaluate the high temperature risk.展开更多
The effects of yield increase and mechanism of site-specific nitrogen management （SSNM） in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experime...The effects of yield increase and mechanism of site-specific nitrogen management （SSNM） in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experiments of two fertilization methods, SSNM and farmer＇s fertilization practice （FFP） were conducted to study their effects on the quality and dry matter accumulation of rice population, as well as N uptake. Compared with FFP, SSNM significantly decreased the average N rate by 33.8%, significantly increased average ear-bearing tiller rate and LAI for grain-filling stage by 12.3% and 14.1-27.6%, correspondingly, improved dry matter weight and N uptake after heading period by 4.3-29.1% and 11.8-55.1% （P 〈 0.05）, and heightened recovery efficiency and agronomic efficiency by 38.5-133.4% （P 〈 0.05） and 39.8-194.3% （P 〈 0.05）, respectively, as well as increased the average yield by 9.8% in 2004 and 2005. The results indicated that the accumulation rate of dry matter and N increased the rice yield and N use efficiency, because of improving rice population quality and increasing LAI after heading period.展开更多
The effects of calcium application rate on dry matter accumulation and yield of peanut were studied under high-yielding field condition. The variety used for the study was Tang A8252( Spanish peanut). The results show...The effects of calcium application rate on dry matter accumulation and yield of peanut were studied under high-yielding field condition. The variety used for the study was Tang A8252( Spanish peanut). The results showed that number of full fruit,dry weight per plant,kernel yield,and pod yield all increased with calcium application increased,and they decreased when calcium application rate was more than150 kg/ha. Both the height of main stem and the length of side shoot decreased with calcium application increased. Therefore,to obtain the optimal agronomic character index and the highest yield benefit,the suggested calcium application rate would be 150 kg/ha for peanut.展开更多
The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen (N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their t...The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen (N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their temporal stabilities with temporal stability maps; and assess the potential for site-specific management in each pasture-growing period using classified management maps. At cut 1, the spatial patterns of DM and N yields proved to be well defined and temporally stable and were likely to be due to differences in the net N mineralization rates across the field during spring. In contrast, at cut 2, the patterns of DM production were patchy and temporally unstable. It was concluded that, in principle, a simple site-specific approach to N fertilization would be possible in this field during spring at cut 1. At later harvests, the rationale for a site-specific approach to fertilizer management was less clear with logistics appearing to be more complex and less feasible.展开更多
The objective of this study was to assess soil tillage methods by years interaction for dry matter of plant yield of maize(Zea mays L.) grown in West Poland by the additive main effects and multiplicative interaction ...The objective of this study was to assess soil tillage methods by years interaction for dry matter of plant yield of maize(Zea mays L.) grown in West Poland by the additive main effects and multiplicative interaction model. The study comprised four soil tillage methods, analysed in 12 years through field trials arranged in a randomized complete block design, with four replicates. Dry matter of plant yield of the tested soil tillage methods varied from 86.7 dt ha(for no-plough tillage in 2005) to 246.4 dt ha(for complete conventional tillage in 2012), with an average of 146.6 dt ha. In the variance analysis, 49.07% of the total dry matter of plant yield variation was explained by years, 12.69% by differences between soil tillage methods, and 10.53% by soil tillage methods by years interaction. Dry matter of plant yield is highly influenced by soil tillage methods by years factors.展开更多
Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangel...Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangeland on relative frequency, dry matter yield and nutritive value of dominant grasses in an area invaded by Euryops floribundus. A plot of 2.5 ha was measured and the boundaries demarcated using tape measure and steal pins, the plot was further divided into two subplots of 1ha each which were 5 m apart. One subplot was fenced and protected from grazing livestock, while one subplot was grazed continuously and not fenced. Three parallel belt transects of 100 m × 2 m with 3 m apart were laid out in both subplots. Woody plants occurring within the transects were identified and recorded to determine density. In each subplot, a 0.25 m<sup>2</sup> quadrant measuring was thrown randomly to take detailed records on plant species, relative frequency of species and herbage biomass. Four dominant species at the two sites were harvested to determine the nutritive value. Results indicate that grazing exclusion (GE) facilitates grass species diversity, subsequently sixteen and thirteen grasses species were recorded in the GE and uncontrolled grazed (UG) sites, respectively. Eragrostis chloromelas (21.7%), and Themeda triandra (13.2%) had high relative frequencies in the GE site. Highest biomass production was recorded in the GE site (1400 kg·ha<sup>-1</sup>) compared to UG site (1102 kg·ha<sup>-1</sup>). Crude protein content was relatively lower at UG site (5.4% - 5.8%) as compared to GE site (7.2% - 7.8%). It was concluded that, GE showed a positive impact on a relative frequency (%), dry matter yield and crude protein content. UG creates a conducive environment for Euryops recruitment. Further studies are required to examine the impact of GE in long-term trial setup.展开更多
The variety "Aifeng" was used as experimental material,and the stem diameter,plant height,the number of leaves and yield of P. vulgaris under three ways of ridge culture (bedding,high ridge and M ridge) were...The variety "Aifeng" was used as experimental material,and the stem diameter,plant height,the number of leaves and yield of P. vulgaris under three ways of ridge culture (bedding,high ridge and M ridge) were observed and detected to study the effects of different ridge cultures on the growth and yield. The results showed that the stem diameter,plant height,the number of leaves and yield under M ridge culture were higher than that of bedding and high ridge.展开更多
The high premium placed on the organically produced cocoa in the international market coupled with its health and environmental benefits necessitated recent focus on research into the use of agricultural wastes as sou...The high premium placed on the organically produced cocoa in the international market coupled with its health and environmental benefits necessitated recent focus on research into the use of agricultural wastes as source of nutrients in cocoa (T. cacao) production. The study was carried out at the Cocoa Research Institute of Nigeria (CRIN), Ibadan (Lat. 7°25'N Long. 3°25'E), South-western, Nigeria during the 2010/2011 seedling production season to compare the effects of NPK (20:10:10) fertilizer, Cocoa Pod Husk and Oil Palm Bunch Ash (CPHA and OPA) on the seedling growth and dry matter yield of cocoa (T. cacao). Equivalent amount of different rates of two nutrients sources CPHA and OPA were applied one month after planting at 0, 1, 2, 3, 4 and 5 t/ha respectively, recommended rate of 10 kg·N of the conventional NPK (20:10:10). Fertilizer was used as reference fertilizer. Results indicated that all the fertilizer materials positively and significantly (p > 0.05) increased the growth parameters considered. The influence of the ash materials irrespective of sources on the nutrient uptake, dry matter yield of cocoa seedlings and shoot to root ratio were either higher than or had a comparable results with the reference fertilizer (NPK 20:10:10). CPHA and OPA applied at a rate of 4 t/ha significantly (p > 0.05) increased the plant height and root length of cocoa seedlings respectively relative to control and in—organic fertilizer and could therefore be recommended for the prospective and existing Nigerian cocoa farmers for raising their seedlings in the nursery before transplanting to the field.展开更多
The drought in spring leads to the lack of soil water, which influents sprout and bud of crops, which furthermore affects growth and yield of crops. Studying the technology integration of bed-irrigating sowing, the me...The drought in spring leads to the lack of soil water, which influents sprout and bud of crops, which furthermore affects growth and yield of crops. Studying the technology integration of bed-irrigating sowing, the mending irrigation of seedling stage and the effect of water-saving of ridge plotted field, analyzing the finger of yield and dry matter accumulation, water-saving technology integration have good effects on water-saving, water storage and increasing moisture on soil and enhancement of soybean yield.展开更多
Under the current context of climate change, supplementary irrigation may be needed for crop production resilience. We determined the effects of supplementary irrigation on sorghum grain yield in the dry Savannah regi...Under the current context of climate change, supplementary irrigation may be needed for crop production resilience. We determined the effects of supplementary irrigation on sorghum grain yield in the dry Savannah region of Togo. A two-year trial was conducted in a controlled environment at AREJ, an agro-ecological center in Cinkassé. The plant material was sorghum variety Sorvato 28. The experimental design was a Completely Randomized Block with three replications and three treatments as follows: T0 control plot (rainfed conditions);T1 (supplementary irrigation from flowering to grain filling stage) and T2 (supplementary irrigation from planting to grain filling stage). Two irrigation techniques (furrow and Californian system) were used under each watering treatment. The results showed that irrigation technique significantly affected panicle length with no effect on 1000 grains mass. Panicle length and grain yields varied from 15.59 to 25.71 cm and 0.0 to 2.06 t∙h−1, respectively, with the highest values (25.66 cm and 2.06 t∙h−1, respectively) under the T2 treatment with the California system-based supplementary irrigation. The comparison of results obtained on treatment T0 and T2, shows that supplementary irrigation increased the yields by at least 68.62%. Supplementary irrigation during sowing and growing season (T2) improved sorghum yields in the dry savannahs of Togo, with a better performance of the California irrigation system.展开更多
We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ...We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ) and Teyou 63(Longtepu A/Minhui 63), as well as theircommon restorer line, Minhui 63 (elite cultivar展开更多
[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the secon...[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the second last leaf （L2）,removing upper part of spike （L3） and controlling （CK） were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat＇s 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat＇s 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat.展开更多
The effect of three different N-fertilization levels （NI： 625, N2：385 and N3：770 kg hal; where in case of N1 was used the 3-6-10＋3MGO＋30% OM and in cases of N2-N3 the 26-0-0 fertilizers） on fresh and dry weight...The effect of three different N-fertilization levels （NI： 625, N2：385 and N3：770 kg hal; where in case of N1 was used the 3-6-10＋3MGO＋30% OM and in cases of N2-N3 the 26-0-0 fertilizers） on fresh and dry weight of the perennial Rosmarinus officinalis （upright cultivar） was investigated during the 2nd year after establishment at the Experimental Farm of the Technological Educational Institute of Thessaly in Greece （TEI; Larissa plain） in 2015. It is well documented that the crop reaches its potential yield on the third year of cultivation and continues producing biomass for as long as eight years. Complete weather data （air temperature, radiation, air humidity, precipitation） were recorded hourly in an automatic meteorological station, which was installed to the experimental farm of TEI. Upon harvest （November 3rd 2015）, the crop reached a maximum fresh yield of 11.67 tons per hectare and dry yield of 4.3, respectively. The average fresh weight was 8.2, 8.4 and 8.9 t hal and the dry weight were 2.6, 3.1 and 3.2 t ha-1 for the N1, N2 and N3 levels, respectively. Furthermore the higher moisture content was observed in the case of N1 level （68%）. Therefore, the above data show that rosemary cultivation could be a promising alternative crop, especially in case of the consideration that average selling price of dry rosemary in Greece is 3.5 ∈ kg^-1 and the average gross income exceeds the amount of 10,000 ∈ ha^-1.展开更多
文摘Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer is a very important water source when growing alfalfa in Southwest Kansas and unfortunately, the water level of the Ogallala Aquifer is shrinking. The objective of this study was to determine the optimum cutting interval that optimizes dry matter yield and nutritive values of alfalfa. Alfalfa was harvested with different cutting intervals, i.e., every 28, 35, 42 and 49 day, which was equivalent of 5, 4, 4, and 3 cuttings per year, respectively in 2013 and 2014. Based on 2-yr total yield, by delaying alfalfa harvest by 21 days, i.e., from every 28th day to 49th day, alfalfa yield increased by 2.25 Mg/ha whereas by 5.58 Mg/ha by delaying cutting intervals from every 28th day to 42nd day. Although harvesting alfalfa every 42nd day had the same cutting frequency as the 35th day treatment (i.e., 4 cuttings per year), the treatment harvesting every 42nd day had significantly higher alfalfa yield than 35th day cutting interval. Alfalfa yield increased by approximately 20% by delaying one week for harvesting alfalfa from 35th to 42nd day interval, based on dry matter yields of 2013 and 2014. As cutting interval increased from every 28th to 49th day, crude protein (CP) content decreased. In contrast to CP, acid detergent fiber and neutral detergent fiber increased as the cutting interval and stage of maturity increased in 2013 and 2014. The results suggest that alfalfa producers in Southwest Kansas possibly could reduce the cutting frequency from 5 to 4 per year. Cutting interval of every 42nd day between harvests appears to be the optimum when considered a dry matter yield and nutritive values in alfalfa.
基金Bangladesh Agricultural Research Institute (BARI), Ministry of Agriculture, Bangladesh for providing fund and facilities for sustainable irrigation and water management practices
文摘Sustainable irrigation method is now essential for adaptation and adoption in the areas where water resources are limited. Therefore, a field experiment was conducted to test the performance of alternate wetting and drying furrow irrigation（AWDFI） on crop growth, yield, water use efficiency（WUE）, fruit quality and profitability analysis of tomato. The experiment was laid out in randomized complete block design with six treatments replicated thrice during the dry seasons of 2013-2014 and 2014-2015. Irrigation water was applied through three ways of furrow： AWDFI, fixed wetting and drying furrow irrigation（FWDFI） and traditional（every） furrow irrigation（TFI）. Each irrigation method was divided into two levels： irrigation up to 100 and 80% field capacity（FC）. Results showed that plant biomass（dry matter） and marketable fruit yield of tomato did not differ significantly between the treatments of AWDFI and TFI, but significant difference was observed in AWDFI and in TFI compared to FWDFI at same irrigation level. AWDFI saved irrigation water by 35 to 38% for the irrigation levels up to 80 and 100% FC, compared to the TFI, respectively. AWDFI improved WUE by around 37 to 40% compared to TFI when irrigated with 100 and 80% FC, respectively. Fruit quality（total soluble solids and pulp） was found greater in AWDFI than in TFI. Net return from AWDFI technique was found nearly similar compared to TFI and more than FWDFI. The benefit cost ratio was viewed higher in AWDFI than in TFI and FWDFI by 2.8, 8.7 and 11, 10.4% when irrigation water was applied up to 100 and 80% FC, respectively. Unit production cost was obtained lower in AWDFI compared to TFI and FWDFI. However, AWDFI is a useful water-saving furrow irrigation technique which may resolve as an alternative choice compared with TFI in the areas where available water and supply methods are limited to irrigation.
基金the National Basic Research Program(973 Program,No.2012CB114306)the National Natural Science Foundation of China(Nos.31461143015+5 种基金31271641,31471438)the National Key Technology Support Program of China(Nos.2014AA10A6052012BAD04B08)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Top Talent Supporting Program of Yangzhou University(No.2015-01)Jiangsu Creation Program for Postgraduate Students(No.KYZZ15_0364)
文摘To meet the major challenge of increasing rice production to feed a growing population under increasing water scarcity,many water-saving regimes have been introduced in irrigated rice,such as an aerobic rice system,non-flooded mulching cultivation,and alternate wetting and drying(AWD).These regimes could substantially enhance water use efficiency(WUE) by reducing irrigation water.However,such enhancements greatly compromise grain yield.Recent work has shown that moderate AWD,in which photosynthesis is not severely inhibited and plants can rehydrate overnight during the soil drying period,or plants are rewatered at a soil water potential of-10 to-15 k Pa,or midday leaf potential is approximately-0.60 to-0.80 MPa,or the water table is maintained at 10 to 15 cm below the soil surface,could increase not only WUE but also grain yield.Increases in grain yield WUE under moderate AWD are due mainly to reduced redundant vegetative growth;improved canopy structure and root growth;elevated hormonal levels,in particular increases in abscisic acid levels during soil drying and cytokinin levels during rewatering;and enhanced carbon remobilization from vegetative tissues to grain.Moderate AWD could also improve rice quality,including reductions in grain arsenic accumulation,and reduce methane emissions from paddies.Adoption of moderate AWD with an appropriate nitrogen application rate may exert a synergistic effect on grain yield and result in higher WUE and nitrogen use efficiency.Further research is needed to understand root–soil interaction and evaluate the long-term effects of moderate AWD on sustainable agriculture.
基金sponsored by the National Natural Science Foundation of China(31461143015,31271641,31471438)the National Key Technology Support Program of China(2014AA10A605,216YFD0300206-4)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),Chinathe Jiangsu Creation Program for Post-graduation Students,China(KYZZ15_0364)
文摘This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency （WUE） under alternate wetting and drying （AWD） irrigation than check rice. Two super rice cultivars and two elite check rice cultivars were grown in pots with three soil moisture levels, well watered （WW）, moderate water deficit （MWD） and severe water deficit （SWD）. Two cultivars, each for super rice and check rice, were grown in field with three irrigation regimes, alternate wetting and moderate drying （AWMD）, alternate wetting and severe drying （AWSD） and conventional irrigation （CI）. Compared with that under WW, grain yield was significantly decreased under MWD and SWD treatments, with less reduction for super rice than for check rice. Super rice had higher percentage of productive tillers, deeper root distribution, higher root oxidation activity, and greater aboveground biomass production at mid and late growth stages than check rice, especially under WMD and WSD. Compared with CI,AWMD increased, whereasAWSD decreased grain yield, with more increase or less decrease for super rice than for check rice. Both MWD and SWD treatments and eitherAWMD orAWSD regime significantly increased WUE compared with WW treatment or CI regime, with more increase for super rice than for check rice. The results suggest that super rice has a stronger ability to cope with soil water deficit and holds greater promising to increase both grain yield and WUE by adoption of moderate AWD irrigation.
基金supported by the National Basic Research Program of China (2010CB951302-2)the National Natural Science Foundation of China (51109214 and 31101074)
文摘Climate change is recognized to increase the frequency and severity of extreme temperature events. At flowering and grain filling stages, risk of high temperature stress （HTS） on rice might increase, and lead to declining grain yields. A regulated cabinet experiment was carried out to investigate effects of high temperature stress on rice growth at flowering and grain- filling stages. Results showed that no obvious decrease pattern in net photosynthesis appeared along with the temperature rising, but the dry matter allocation in leaf, leaf sheath, culm, and panicle all changed. Dry weight of panicle decreased, and ratio of straw to total above ground crop dry weight increased 6-34% from CK, which might have great effects on carbon cycling and green house gas emission. Grain yield decreased significantly across all treatments on average from 15 to 73%. Occurrence of HTS at flowering stage showed more serious influence on grain yield than at grain filling stage. High temperature stress showed negative effects on harvest index. It might be helpful to provide valuable information for crop simulation models to capture the effects of high temperature stress on rice, and evaluate the high temperature risk.
文摘The effects of yield increase and mechanism of site-specific nitrogen management （SSNM） in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experiments of two fertilization methods, SSNM and farmer＇s fertilization practice （FFP） were conducted to study their effects on the quality and dry matter accumulation of rice population, as well as N uptake. Compared with FFP, SSNM significantly decreased the average N rate by 33.8%, significantly increased average ear-bearing tiller rate and LAI for grain-filling stage by 12.3% and 14.1-27.6%, correspondingly, improved dry matter weight and N uptake after heading period by 4.3-29.1% and 11.8-55.1% （P 〈 0.05）, and heightened recovery efficiency and agronomic efficiency by 38.5-133.4% （P 〈 0.05） and 39.8-194.3% （P 〈 0.05）, respectively, as well as increased the average yield by 9.8% in 2004 and 2005. The results indicated that the accumulation rate of dry matter and N increased the rice yield and N use efficiency, because of improving rice population quality and increasing LAI after heading period.
基金Supported by Liaoning Innovation Team Project of Peanut Industry of National Modern Agricultural Industry Technology System(2016007022)
文摘The effects of calcium application rate on dry matter accumulation and yield of peanut were studied under high-yielding field condition. The variety used for the study was Tang A8252( Spanish peanut). The results showed that number of full fruit,dry weight per plant,kernel yield,and pod yield all increased with calcium application increased,and they decreased when calcium application rate was more than150 kg/ha. Both the height of main stem and the length of side shoot decreased with calcium application increased. Therefore,to obtain the optimal agronomic character index and the highest yield benefit,the suggested calcium application rate would be 150 kg/ha for peanut.
基金Project supported by the Higher Education Links between China and UK (No. SHA/992/308)
文摘The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen (N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their temporal stabilities with temporal stability maps; and assess the potential for site-specific management in each pasture-growing period using classified management maps. At cut 1, the spatial patterns of DM and N yields proved to be well defined and temporally stable and were likely to be due to differences in the net N mineralization rates across the field during spring. In contrast, at cut 2, the patterns of DM production were patchy and temporally unstable. It was concluded that, in principle, a simple site-specific approach to N fertilization would be possible in this field during spring at cut 1. At later harvests, the rationale for a site-specific approach to fertilizer management was less clear with logistics appearing to be more complex and less feasible.
文摘The objective of this study was to assess soil tillage methods by years interaction for dry matter of plant yield of maize(Zea mays L.) grown in West Poland by the additive main effects and multiplicative interaction model. The study comprised four soil tillage methods, analysed in 12 years through field trials arranged in a randomized complete block design, with four replicates. Dry matter of plant yield of the tested soil tillage methods varied from 86.7 dt ha(for no-plough tillage in 2005) to 246.4 dt ha(for complete conventional tillage in 2012), with an average of 146.6 dt ha. In the variance analysis, 49.07% of the total dry matter of plant yield variation was explained by years, 12.69% by differences between soil tillage methods, and 10.53% by soil tillage methods by years interaction. Dry matter of plant yield is highly influenced by soil tillage methods by years factors.
文摘Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangeland on relative frequency, dry matter yield and nutritive value of dominant grasses in an area invaded by Euryops floribundus. A plot of 2.5 ha was measured and the boundaries demarcated using tape measure and steal pins, the plot was further divided into two subplots of 1ha each which were 5 m apart. One subplot was fenced and protected from grazing livestock, while one subplot was grazed continuously and not fenced. Three parallel belt transects of 100 m × 2 m with 3 m apart were laid out in both subplots. Woody plants occurring within the transects were identified and recorded to determine density. In each subplot, a 0.25 m<sup>2</sup> quadrant measuring was thrown randomly to take detailed records on plant species, relative frequency of species and herbage biomass. Four dominant species at the two sites were harvested to determine the nutritive value. Results indicate that grazing exclusion (GE) facilitates grass species diversity, subsequently sixteen and thirteen grasses species were recorded in the GE and uncontrolled grazed (UG) sites, respectively. Eragrostis chloromelas (21.7%), and Themeda triandra (13.2%) had high relative frequencies in the GE site. Highest biomass production was recorded in the GE site (1400 kg·ha<sup>-1</sup>) compared to UG site (1102 kg·ha<sup>-1</sup>). Crude protein content was relatively lower at UG site (5.4% - 5.8%) as compared to GE site (7.2% - 7.8%). It was concluded that, GE showed a positive impact on a relative frequency (%), dry matter yield and crude protein content. UG creates a conducive environment for Euryops recruitment. Further studies are required to examine the impact of GE in long-term trial setup.
基金Supported by Water-saving and Efficient Model Research of Dry Land Vegetable Planting (2007BAD88B03-3-2)
文摘The variety "Aifeng" was used as experimental material,and the stem diameter,plant height,the number of leaves and yield of P. vulgaris under three ways of ridge culture (bedding,high ridge and M ridge) were observed and detected to study the effects of different ridge cultures on the growth and yield. The results showed that the stem diameter,plant height,the number of leaves and yield under M ridge culture were higher than that of bedding and high ridge.
文摘The high premium placed on the organically produced cocoa in the international market coupled with its health and environmental benefits necessitated recent focus on research into the use of agricultural wastes as source of nutrients in cocoa (T. cacao) production. The study was carried out at the Cocoa Research Institute of Nigeria (CRIN), Ibadan (Lat. 7°25'N Long. 3°25'E), South-western, Nigeria during the 2010/2011 seedling production season to compare the effects of NPK (20:10:10) fertilizer, Cocoa Pod Husk and Oil Palm Bunch Ash (CPHA and OPA) on the seedling growth and dry matter yield of cocoa (T. cacao). Equivalent amount of different rates of two nutrients sources CPHA and OPA were applied one month after planting at 0, 1, 2, 3, 4 and 5 t/ha respectively, recommended rate of 10 kg·N of the conventional NPK (20:10:10). Fertilizer was used as reference fertilizer. Results indicated that all the fertilizer materials positively and significantly (p > 0.05) increased the growth parameters considered. The influence of the ash materials irrespective of sources on the nutrient uptake, dry matter yield of cocoa seedlings and shoot to root ratio were either higher than or had a comparable results with the reference fertilizer (NPK 20:10:10). CPHA and OPA applied at a rate of 4 t/ha significantly (p > 0.05) increased the plant height and root length of cocoa seedlings respectively relative to control and in—organic fertilizer and could therefore be recommended for the prospective and existing Nigerian cocoa farmers for raising their seedlings in the nursery before transplanting to the field.
基金Nature Science Fund Project in Heilongjiang Province (C2004-10)
文摘The drought in spring leads to the lack of soil water, which influents sprout and bud of crops, which furthermore affects growth and yield of crops. Studying the technology integration of bed-irrigating sowing, the mending irrigation of seedling stage and the effect of water-saving of ridge plotted field, analyzing the finger of yield and dry matter accumulation, water-saving technology integration have good effects on water-saving, water storage and increasing moisture on soil and enhancement of soybean yield.
文摘Under the current context of climate change, supplementary irrigation may be needed for crop production resilience. We determined the effects of supplementary irrigation on sorghum grain yield in the dry Savannah region of Togo. A two-year trial was conducted in a controlled environment at AREJ, an agro-ecological center in Cinkassé. The plant material was sorghum variety Sorvato 28. The experimental design was a Completely Randomized Block with three replications and three treatments as follows: T0 control plot (rainfed conditions);T1 (supplementary irrigation from flowering to grain filling stage) and T2 (supplementary irrigation from planting to grain filling stage). Two irrigation techniques (furrow and Californian system) were used under each watering treatment. The results showed that irrigation technique significantly affected panicle length with no effect on 1000 grains mass. Panicle length and grain yields varied from 15.59 to 25.71 cm and 0.0 to 2.06 t∙h−1, respectively, with the highest values (25.66 cm and 2.06 t∙h−1, respectively) under the T2 treatment with the California system-based supplementary irrigation. The comparison of results obtained on treatment T0 and T2, shows that supplementary irrigation increased the yields by at least 68.62%. Supplementary irrigation during sowing and growing season (T2) improved sorghum yields in the dry savannahs of Togo, with a better performance of the California irrigation system.
文摘We studied the characteristics of dry matterproduction and matter partitioning in hybridrice and the relationships of them with heterot-ic effect in 1993. Two popular indica hybrids, Shanyou 63(Zhenshan 97A/Minhui 63 ) and Teyou 63(Longtepu A/Minhui 63), as well as theircommon restorer line, Minhui 63 (elite cultivar
基金Supported by Jiangsu High School Natural Science Fund(09KJB210004)Undergraduate Practice Innovation Project of Nanjing University of Information Science & Technology (09CX0025 )Educational Reform Project of Nanjing University of Information Science &Technology (09JY0036)~~
文摘[Objective] The paper aims to explore the influences of source sink change of wheat at different densities on wheat yield.[Method] 225 （D1） and 320 plant/m2（D2） were adopted,then cutting flag leaf （L1）,the second last leaf （L2）,removing upper part of spike （L3） and controlling （CK） were used to conduct field experiment.[Result] The results showed that both of the two densities of wheat＇s 1 000-grain weight and grain filling rate after anthesis in a decreasing order of L3〉CK〉L2〉L1,and the grain weight per spike and dry matter amount translated after anthesis turned to be CK〉L2〉L1 〉L3.[Conclusion].Both of leaf-cutting and spikelet removing decreased the grain weight per spike and dry matter amount translated after anthesis.Removing upper part of spike increased wheat＇s 1 000-grain weight.But the decreasing of the sink and dry matter amount translated contributed to the decreasing of the yield of wheat.
文摘The effect of three different N-fertilization levels （NI： 625, N2：385 and N3：770 kg hal; where in case of N1 was used the 3-6-10＋3MGO＋30% OM and in cases of N2-N3 the 26-0-0 fertilizers） on fresh and dry weight of the perennial Rosmarinus officinalis （upright cultivar） was investigated during the 2nd year after establishment at the Experimental Farm of the Technological Educational Institute of Thessaly in Greece （TEI; Larissa plain） in 2015. It is well documented that the crop reaches its potential yield on the third year of cultivation and continues producing biomass for as long as eight years. Complete weather data （air temperature, radiation, air humidity, precipitation） were recorded hourly in an automatic meteorological station, which was installed to the experimental farm of TEI. Upon harvest （November 3rd 2015）, the crop reached a maximum fresh yield of 11.67 tons per hectare and dry yield of 4.3, respectively. The average fresh weight was 8.2, 8.4 and 8.9 t hal and the dry weight were 2.6, 3.1 and 3.2 t ha-1 for the N1, N2 and N3 levels, respectively. Furthermore the higher moisture content was observed in the case of N1 level （68%）. Therefore, the above data show that rosemary cultivation could be a promising alternative crop, especially in case of the consideration that average selling price of dry rosemary in Greece is 3.5 ∈ kg^-1 and the average gross income exceeds the amount of 10,000 ∈ ha^-1.
