Pinus densiflora is a pine species native to the Korean peninsula,and seed orchards have supplied mate-rial needed for afforestation in South Korea.Climate vari-ables affecting seed production have not been identified...Pinus densiflora is a pine species native to the Korean peninsula,and seed orchards have supplied mate-rial needed for afforestation in South Korea.Climate vari-ables affecting seed production have not been identified.The purpose of this study was to determine climate variables that influence annual seed production of two seed orchards using multiple linear regression(MLR),elastic net regres-sion(ENR)and partial least square regression(PLSR)mod-els.The PLSR model included 12 climatic variables from 2003 to 2020 and explained 74.3%of the total variation in seed production.It showed better predictive performance(R2=0.662)than the EN(0.516)and the MLR(0.366)mod-els.Among the 12 climatic variables,July temperature two years prior to seed production and July precipitation after one year had the strongest influence on seed production.The time periods indicated by the two variables corresponded to pollen cone initiation and female gametophyte development.The results will be helpful for developing seed collection plans,selecting new orchard sites with favorable climatic conditions,and investigating the relationships between seed production and climatic factors in related pine species.展开更多
[Objectives]This study was conducted to investigate the impact of soybean intercropping on soil fertility in the planting areas of high-quality peach orchards in Shenxi Town,Zunyi City,Guizhou Province.[Methods]Soil s...[Objectives]This study was conducted to investigate the impact of soybean intercropping on soil fertility in the planting areas of high-quality peach orchards in Shenxi Town,Zunyi City,Guizhou Province.[Methods]Soil samples were collected during the seedling,growth,and maturity stages of soybeans from both non-intercropped soil(control check group,CK)and soybean-intercropped soil(Qiandou 11,experimental group,EK).Analysis was conducted on soil fertility properties,including alkali-hydrolyzable N,available P,and available K.[Results]The impact of soybean intercropping on soil physicochemical properties was primarily manifested as the increased levels of alkali-hydrolyzable N and available K and the decreased level of available P in the soil during the seedling,growing,and maturity stages.Overall,this approach optimized and enhanced soil fertility in the peach orchards,providing a viable pathway for soil improvement in peach orchards located in karst areas.[Conclusions]The findings of this study provide a scientific basis for the high-quality development of high-quality peach orchards.展开更多
[Objectives]This study was conducted to clarify the enrichment and paucity of trace elements in the soil environment of peach orchards in Zunyi City,and to provide reference for supplementary application of microeleme...[Objectives]This study was conducted to clarify the enrichment and paucity of trace elements in the soil environment of peach orchards in Zunyi City,and to provide reference for supplementary application of microelement fertilizers and high-quality peach production in peach orchards.[Methods]Taking the soil of three typical peach orchards(Taoli Renjia peach orchard,Pengrui peach orchard and Taohuadao peach orchard)in Shenxi Town,Honghuagang District,Zunyi City as the research object,the contents of trace elements in soil were analyzed through field sampling and indoor determination of trace elements.[Results]The effective contents of trace elements in the soil of peach orchard bases in the study area were at a medium level,and the soil of the peach orchards was rich in available Fe and Se.The contents of available Cu,Mo and Mn were relatively rich.The contents of available B were not high overall.The contents of available Zn were at a moderate to low level overall.The soil of Taoli Renjia peach orchard was relatively rich in trace elements.[Conclusions]The research results can provide a scientific basis for the production of high-quality crispy peaches in peach orchards.展开更多
The aim was to analyze effects of jujube planting years on changes of soil nutrient elements and explore the causes of orchard degradation by researching variation characteristics of soil nutrient contents in orchards...The aim was to analyze effects of jujube planting years on changes of soil nutrient elements and explore the causes of orchard degradation by researching variation characteristics of soil nutrient contents in orchards with different planting years, providing theoretical support for the soil degradation of jujube or-chards. [Method] Soil samples were col ected in depth at 0-20 and 20-40 cm from the sites in or out of tree canopy scope in jujube orchards with 3, 5 and 7 plan-ning-years, to analyze contents of available N, P and K, organic matter, total N, salts, and trace elements, as wel as changes of nutritional elements. [Result] Avail-able boron, copper, iron, manganese, zinc and available potassium in soils of jujube orchards with 3, 5 and 7 years planting history reduced as planting year increased, which coincided with that in the soil of 20-40 cm. [Conclusion] Because trace ele-ments are never applied in southern Xinjiang, available B, Cu, Fe, Mn, and Zn and available K would be consumed by tree root growth. Due to root distribution differ-ences and ploughing effects in fields, the contents of nutrients tend to be volatile in or out of tree canopy scope. Tree root in deeper soils absorbs more nutrients, and soil nutrients would decrease dramatical y if additional chemical fertilizers are not provided, leading to soil degradation.展开更多
In order to research environment parameters and physiological indices of high-quality and high-yield apple trees, two orchards with young and mature apples trees were investigated to explore structural parameter of ap...In order to research environment parameters and physiological indices of high-quality and high-yield apple trees, two orchards with young and mature apples trees were investigated to explore structural parameter of apple tree and community, and some physiological indices in fields and by room measurements. The results showed that tree height of high-quality orchard was in the range of 260 to 290 cm, branch angle in 70°-75°, and orchard coverage rate in 75%-94%, and the connec-tion rates between rows and trees were lower. Furthermore, the total branches of mature orchard reached 1.04 ×106 per hm2, while the young orchard was 8.79 ×105 per hm2; the leaves were thick and chlorophyl content was high, with SPAD value at 58.22. Additional y, the photosynthesis of the orchard was strong, and net photo-synthetic rate was 17.48-21.8 μmolCO2/（m2·s）. The proportions of lateral shoot of bearing part were 81% and 75% respectively.展开更多
Planting mulch grasses in orchards,as a technique to build ecological orchards,can be one of the strategic approaches for rural revitalization.This study sorted out the common varieties of mulch grasses and analyzed t...Planting mulch grasses in orchards,as a technique to build ecological orchards,can be one of the strategic approaches for rural revitalization.This study sorted out the common varieties of mulch grasses and analyzed their application statuses in orchards of southern China.According to different utilization purposes of mulch grasses in orchards,scientific suggestions were given from aspects of grass selection,cultivation techniques,management methods and use modes.The study will provide reference for the construction of ecological orchards in southern China.展开更多
In the recent years The Mediterranean Fruit fly Ceratitis capitata is distributed in the orchards of central Iraq and caused highly economic losses. This study was conducted in orchards in central Iraq during 2009 and...In the recent years The Mediterranean Fruit fly Ceratitis capitata is distributed in the orchards of central Iraq and caused highly economic losses. This study was conducted in orchards in central Iraq during 2009 and 2010 and made field survey of the insect in four types of orchards （Citrus, Apricot, Figs ＆ Citrus and A mixture of fruit trees） and used for this purpose Tephri Traps supplied with Q-Lure and dimethyl dichloroviny phosphate （DDVP）. The present preliminary study has shown that the Mediterranean fruit fly C. capitata has a year round presence in fruit orchards in central Iraq and reached its highest ntunerical density of the pest in citrus orchards during of November and December were 345 and 363 insect/trap per month in citrus orchards and the least numerical density during of January and February while the highest numerical density of the insect in orchards of Apricot in March 2010, Figs ＆ Citrus in August 2009 and a Mixture of fruit trees in November 2009 were 45, 116, 311 insect/trap per month respectively. The population density of the pest was highest is started 2010 compared with 2009, but the high temperature degree （46-51℃） in August 2010 caused decreasing the population density of this pest. C. capitata caused highly economic losses in citrus reached 68% and 71% of the Mandarin and Kaki fruits respectively Currently in Iraq to fight no control method to reduce the economic losses caused by this pest except the use of pesticides GF-120.展开更多
Based on the investigation of 56 soil samples( 0-30 cm) in citrus orchards of Guangxi,the content of soil organic matter and available nutrients as well as their correlations in the citrus orchards were studied. The r...Based on the investigation of 56 soil samples( 0-30 cm) in citrus orchards of Guangxi,the content of soil organic matter and available nutrients as well as their correlations in the citrus orchards were studied. The results showed that soil was rich in organic matter,and the proportion of soil samples deficient in available N,P and K was 30. 36%,32. 14% and 28. 57% respectively. Soil was seriously deficient in soil available Ca,Mg and B,while the content of soil available Fe and Cu in soil was too high. There were significant or extremely significant positive or negative correlations between soil pH,organic matter and several available nutrients. It is recommended to apply Mg fertilizer,B fertilizer,lime or other alkaline fertilizer and reduce the spraying of fungicides containing Cu in the citrus orchards.展开更多
Black locust （Robinia pseudoacacia L.） is one of the most important stand-forming tree species in Hungary and its impor- tance is increasing in many countries. The main aim of the discussed new selection programme i...Black locust （Robinia pseudoacacia L.） is one of the most important stand-forming tree species in Hungary and its impor- tance is increasing in many countries. The main aim of the discussed new selection programme is to identify black locust clones with good performance and good form for setting up clonal seed orchards. As a result of selection programme 16 new black locust clones have been improved. In spring 2002 a black locust seed orchard was established with the newly selected clones. About 40% of the plants can be considered to belong to the height growth rate class 1 and 2. Hungary was the first country where micropropagated black locust planting material was used for seed orchard establishment.展开更多
The main objective of this study was to investigate the presence of natural endophytic Beauveria bassiana within date palm tissues using molecular technique and measure their field efficacies in controlling Dubas bug,...The main objective of this study was to investigate the presence of natural endophytic Beauveria bassiana within date palm tissues using molecular technique and measure their field efficacies in controlling Dubas bug, Ornmatissus lybicus （Deberg）. Two entomopathogenic B. bassiana isolates （MARD 108 and 100） were isolated from date palm, Phoenix dactylifera L. leaves; in addition, one isolate （MARD 92） originally from soil was identified to have endophytic property. Concentration of 1 × 10^9 conidia/mL of each of three endophytic isolates was used in field experiments targeting Dubas bug nymphs via injection tree trunks. The results indicated that the high mortality rates reached 92%, 96% and 100% with infliction of the three endophytic isolates after 15 d from the treatment. The successful establishment of the fungal isolates in the date palm tissue was determined using B. bassiana species-specific primer for the first time via using conventional polymerase chain reaction （PCR） amplification technique before and after injection, and the positive gel band representation was the identification signs. The novel results depicted for the first time the presence of natural endophytic B. bassiana isolates within date palm tissues and their field efficacies in controlling Dubas bug, O. lybicus （Deberg） infestation.展开更多
This study to examine soil fertility status was conducted on 10 citrus plantations in Hau Giang province within the Vietnamese Mekong Delta, Vietnam. Fruit trees are mostly grown on the raised beds to avoid annual flo...This study to examine soil fertility status was conducted on 10 citrus plantations in Hau Giang province within the Vietnamese Mekong Delta, Vietnam. Fruit trees are mostly grown on the raised beds to avoid annual flood with alluvial soil type. Soil sampling was done in the dry season of 2010 at two soil depths, for each raised bed. Development ages of raised beds were represented by two groups, young age group (≤ 30 years) and old age group (> 30 years). For chemical analysis, pH, organic matter, CEC, total nitrogen, NH4+, NO3– and exchangeable Ca, Mg and K were determined. The results showed that the pH (water) was strongly acid. The CEC was in average 19.2 cmol+.kg–1 in topsoil (0 - 20 cm depth) and 18.7 cmol+.kg–1 in subsoil (20 - 50 cm depth) for young age group. Similarly, the CEC was 16.7 cmol+.kg–1 in topsoil and 15.8 cmol+.kg–1 in subsoil for old age group. Organic matter on young age group (7.38 and 5.47% on average for topsoil and subsoil respectively) was significantly higher than that of old age group (5.20 and 3.81% on average for topsoil and subsoil respectively). Total nitrogen was not significantly different between the sites for the age groups of raised as well as the soil layers. Ammonium-N levels were excessive, and NO3--N levels were high. Potassium and Mg2+ were significantly different between age groups of raised beds and the same pattern between soil layers, while Ca2+ did not vary significantly. Potassium and Ca2+ levels were moderate, Mg2+ was high and P levels were very high. Soil fertility in the raised beds subjected to an adverse on plant growth and an imbalance in soil nutrients under low pH conditions. Loss of soil quality was exhibited in reduced organic matter with the aging of raised beds.展开更多
Peach Fruit Fly （PFF） Bactrocera zonata （Saunders） and of the Mediterranean fruit fly （MFF） Ceratitis capitata （Wiedemann） are the most of dominant and destructive key pests in fruit orchards in different agro...Peach Fruit Fly （PFF） Bactrocera zonata （Saunders） and of the Mediterranean fruit fly （MFF） Ceratitis capitata （Wiedemann） are the most of dominant and destructive key pests in fruit orchards in different agro-ecosystem in Egypt. Population fluctuations of the Mediterranean fruit fly Ceratitis capitata （Wiedemann） and the peach fly Bactrocera zonata （Saunders） was monitored with lure traps collections in three provinces in the New Valley oases, Western Desert, Egypt. Results showed marked temporal differences in peak trap catches of the two flies in the selected sites all over the entire studied areas. One annual peak of C. capitata was recorded during both October and February and coincided with the ripening period of citrus trees in Kharga oases. However, two annual peaks were recorded during June and September in Bodkholow province and coincided with the ripening period of apple and mango. On the other hand, two annual peaks of B. zonata were recorded in Kharga oases throughout May and September and coincided with the ripening periods of apricot, mango and guava. One annual peak only was recorded round up of September and/or October in both of Moot and Bodkholow in Dakhla oases and coincided with the ripening period of mango, guava and citrus. Occurrence of C. capitata was very limited in comparison with B. zonata. Population fluctuations of the two pests in the studied sites were significantly different. The ability of the used traps in capturing both of C. capitata and B. zonata indicated that the yellow sticky trap was more effective in capturing C. capitata. However, Abdel-Kawi trap was significantly efficient in trapping B. zonata. Occurrence of B. zontata in high numbers all over the study period than C. capitata is considered as a good proof that this invading fly may be consider a vigor competitive tephritid fly to the native fly C. capitata.展开更多
Automated over-tree sprinkler irrigation systems were developed and tested in two orchards located in two separate locations in southern Iran （a 0.17 ha peach orchard and a 0.24 ha orange orchard） to protect peach b...Automated over-tree sprinkler irrigation systems were developed and tested in two orchards located in two separate locations in southern Iran （a 0.17 ha peach orchard and a 0.24 ha orange orchard） to protect peach blossoms and orange trees leaves and fruits from low temperature damage. The experiment used a system that monitored the trees and air temperatures using two thermistors. The water application rate by the irrigation system was determined by an energy balance as implemented by the software FROSTPRO, In the peach orchard, the system was tested during three frost events during the spring of 2003 and three other events during the spring of 2004. The system successfully kept peach flowers above the critical temperature, i.e., -4.0℃ in spring 2004 （control block -4.12℃, and sprinkled block ＋0.5℃） during all events. Similar results were obtained in the orange orchard during three frost events in the winter of 2004, during which the tree temperatures were at least 2.5℃ above the critical temperature. Results from field tests show that the system can effectively protect the peach blossoms from damage. Determination done after the frost events showed a 12% blossom kill in the sprinkled blocks while in the unsprinkled control block a 41.5% blossom kill. Calculations indicated that when using variable application rates, the amount of water used can be reduced by 54.3%. Spatial distribution of minimum temperatures during the three frosts was also studied in Jahrom, Iran. Results showed a significant temperature control in the experimental block, especially in the central part of the orchard, but the block margins （about 3.6% of the total area） were at the risk of low temperature due to the wind drift effects.展开更多
We design a weather-based indemnity index for the insurance against freeze damage to citrus orchards so as to provide technological support for the development of policy-based agriculture. The indices are prepared by ...We design a weather-based indemnity index for the insurance against freeze damage to citrus orchards so as to provide technological support for the development of policy-based agriculture. The indices are prepared by separating a relative meteorological yield from the yield that is dependent on tree age, high-yield and low-yield years, and environmental factors, and then using a risk assessment scheme to determine the percentage yield reduction due to the meteorological hazard. We thus develop a set of indices associated with cold temperature damage with which to construct more severe weather indices in conjunction with the yield percentage decrease. We then combine the insured regional citrus yield index with the insured meteorological counterpart to obtain a weather-based indemnity index for the varying degree of freeze damage to crops. When the freeze damage index （FDI） is greater than -7.0℃ for the coastal belt of Zhejiang Province, China, or greater than -9.0℃ for other regions of Zhejiang, weather-based indemnity index （WBII） is zero, meaning there is no compensation; when the FDI is from -7.0 to -7.9℃ for the coastal belt or from -9.0 to -9.9℃ for other regions, the WBII is 1 with 50% compensation; when the FDI is from -8.0 to -8.9℃ for the coastal belt or from -10.0 to -10.9℃ for other regions, the WBII is 2 with 70% compensation; and when the FDI is less than -9.0℃ for the coastal belt or less than -11.0℃ for other regions, the WBII is 3 with 90% compensation. The weather indemnity indices of insured orchards are developed in the interest of owners, thereby eliminating adverse selection and moral hazard issues and providing timely recompense from the insurer, and resolving the problem of high indemnity cost in agricultural insurance.展开更多
Soil samples were collected from apple orchards 5,15,20,30,and 45 years old,and one adjacent forest soil was used as reference to investigate the free Cu2+ion activity in soil solution and the soil Cu fractionation in...Soil samples were collected from apple orchards 5,15,20,30,and 45 years old,and one adjacent forest soil was used as reference to investigate the free Cu2+ion activity in soil solution and the soil Cu fractionation in the solid phase following long-term application of copper fungicide,Bordeaux mixture,in apple orchards and to investigate the relationships among soil free Cu2+ions,Cu fractionation and soil microbial parameters.The total Cu concentration in the orchard soils varied from 21.8 to 141 mg kg-1,increasing with the orchard age,and the value for the reference soil was 12.5 mg kg-1.The free Cu2+ion concentrations in the soil solutions extracted by 0.01 mol L-1 KNO3 ranged from 3.13×10-8(reference)to 4.08×10-6 mol L-1(45 years-old orchard).The concentration of Cu complexed in the fulvic fraction increased with orchard age from 5.16 to 52.5 mg kg-1.This was also the case for other soil Cu fractions except the residual one.The residual soil Cu remained practically constant,ranging from 4.28 to 5.66 mg kg-1,suggesting that anthropogenic soil Cu mainly existed in the more labile active fractions.Regression analyses revealed that both the free Cu2+ions in the soil solution and the humic acid-complexed Cu fraction in the solid phase were strongly related with soil microbial parameters.展开更多
It is important to understand the effects of temporal changes in microbial communities in the acidic soils of tea orchards with different fertilizers. A field experiment involving organic fertilizer （OF）, chemical f...It is important to understand the effects of temporal changes in microbial communities in the acidic soils of tea orchards with different fertilizers. A field experiment involving organic fertilizer （OF）, chemical fertilizer （CF）, and unfertilized control （CK） treatments was arranged to analyze the temporal changes in the bacterial and archaeal communities at bimonthly intervals based on the 16S ribosomal RNA （rRNA） gene using terminal restriction fragment length polymorphism （T-RFLP） profiling. The abundances of total bacteria, total archaea, and selected functional genes （bacterial and archaeal amoA, bacterial narG, nirK, nirS, and nosZ） were determined by quantitative poly- merase chain reaction （qPCR）. The results indicate that the structures of bacterial and archaeal communities varied significantly with time and fertilization based on changes in the relative abundance of dominant T-RFs. The abundancy of the detected genes changed with time. The total bacteria, total archaea, and archaeal amoA were less abundant in July. The bacterial amoA and denitrifying genes were less abundant in September, except the nirK gene. The OF treatment increased the abundance of the observed genes, while the CF treatment had little influence on them. The soil temperature significantly affected the bacterial and archaeal community structures. The soil moisture was signif- icantly correlated with the abundance of denitrifying genes. Of the soil chemical properties, soil organic carbon was the most important factor and was significantly correlated with the abundance of the detected genes, except the nirK gene. Overall, this study demonstrated the effects of both temporal alteration and organic fertilizer on the structures of mi- crobial communities and the abundance of genes involved in the nitrogen cycle.展开更多
Excessive nitrogen （N） fertilization of high value horticultural crops is a common problem that not only increases the cost to farmers, but also negatively affects crop growth and the environment. A three-year field...Excessive nitrogen （N） fertilization of high value horticultural crops is a common problem that not only increases the cost to farmers, but also negatively affects crop growth and the environment. A three-year field experiment was conducted in an intensive kiwifruit orchard in Shaanxi Province, China to compare the effects of reduced N fertilization applied as urea （U）, and controlled release urea （CRU） on the N nutrition of kiwi vines, fruit yield and quality, and nitrate-N accumulation in the soil profile. The three treatments included a conventional N application rate （CF-U, 900 kg N ha-1 yr-1 as urea）, two reduced N fertilization treatments where the amount of N fertilizer applied as U and CRU was reduced by 25％ in 2013 and 2014, and by 45％ in 2015. The 25 and 45％ reduced N treatments had no adverse effects on the N concentrations in leaves and pruning branches and the fruit yield and quality of kiwi vines. However, they significantly enhanced the partial factor productivity of applied N （PFPN） and the economic benefits, and reduced nitrate accumulation in the 0-200 cm soil profile. The same benefits of reduced N fertilization were observed for both the U and CRU treatments, but the CRU treatment had the added benefit of decreasing the loss of nitrate through leaching. We concluded that the current level of N fertilization in kiwi orchards is very excessive, and reducing the N fertilizer rate by 25-45％ could not only guarantee fruit yield, but also reduce N accumulation and loss.展开更多
Soil organic carbon and nitrogen are used as indexes of soil quality assessment and sustainable land use management. At the same time, soil C/N ratio is a sensitive indicator of soil quality and for assessing the carb...Soil organic carbon and nitrogen are used as indexes of soil quality assessment and sustainable land use management. At the same time, soil C/N ratio is a sensitive indicator of soil quality and for assessing the carbon and nitrogen nutrition balance of soils. We studied the characteristics of soil organic carbon and total nitrogen by investigating a large number of apple orchards in major apple production areas in China. High apple orchard soil organic carbon content was observed in the provinces of Heilongjiang, Xinjiang, and Yunnan, whereas low content was found in the provinces of Shandong, Henan, Hebei, and Shaanxi, with the values ranging between 6.44 and 7.76 g·kg-1. Similar to soil organic carbon, soil total nitrogen content also exhibited obvious differences in the 12 major apple producing provinces. Shandong apple orchard soil had the highest total nitrogen content (1.26 g·kg-1), followed by Beijing (1.23 g·kg-1). No significant difference was noted between these two regions, but their total nitrogen content was significantly higher than the other nine provinces, excluding Yunnan. The soil total nitrogen content for Xinjiang, Heilongjiang, Hebei, Henan, and Gansu was between 0.87 and 1.03 g·kg-1, which was significantly lower than that in Shandong and Beijing, but significantly higher than that in Liaoning, Shanxi, and Shaanxi. Six provinces exhibited apple orchard soil C/N ratio higher than 10, including Heilongjiang (15.42), Xinjiang (13.38), Ningxia (14.45), Liaoning (12.24), Yunnan (11.03), and Gansu (10.63). The soil C/N ratio was below 10 in the remaining six provinces, in which the highest was found in Shaanxi (9.47), followed by Beijing (8.98), Henan (7.99), and Shanxi (7.62), and the lowest was found in Hebei (6.80) and Shandong (6.05). Therefore, the improvement of soil organic carbon should be given more attention to increase the steady growth of soil C/N ratio.展开更多
The kiwifruit orchards with plants growing for over two years were chosen for interplanting of konjak, which takes advantages of complementation of the two plants in terms of habits, reducing water and soil erosions e...The kiwifruit orchards with plants growing for over two years were chosen for interplanting of konjak, which takes advantages of complementation of the two plants in terms of habits, reducing water and soil erosions effectively, and decreasing water evaporation, and konjak diseases. Furthermore, the interplanting doubles planting benefits and constitutes a highly-efficient planting model.展开更多
The Red Soil Hilly Region in South China, where there is a high capacity of carbon(C), and the land use and vegetation cover change greatly, is an important ecological area in the world, and has an important impact on...The Red Soil Hilly Region in South China, where there is a high capacity of carbon(C), and the land use and vegetation cover change greatly, is an important ecological area in the world, and has an important impact on the global carbon cycle and the seasonal fluctuation of atmospheric CO_2. To better evaluate the effects of reclamation systems in orchards converted from grasslands on soil carbon sequestration, we investigated soil organic carbon(SOC) content and stable C isotope(δ^(13)C)composition in three nectarine orchards at Yuchi Experimental Station in South China. Compared with the sloping clean tillage orchard and terraced clean tillage orchard, SOC content in the terraced orchard with grass cover was increased by 14.90% to 38.49%, and 7.40% to 15.33%, respectively. During the 14 years after orchard establishment, the soil organic matter sources influenced both δ^(13)C distribution with depth and carbon replacement. SOC turnover of the upper soil layer in the terraced orchard with grass cover(a mean 63.05% of replacement in the 20 cm after 14 years) was 1.59 and 1.41 times larger than that of the sloping clean tillage orchard and terraced clean tillage orchard under subtropical conditions, respectively. The equilibrium value of soil organic carbon in the three treatments ranged from 16.067 to 25.608 g/kg under the experimental conditions. The equilibrium value of soil organic carbon in the surface layer under grass cover was 54.801 t/hm^2, and the carbon sequestration potential was 24.695 1 t/hm^2.展开更多
基金supported by the National Institute of Forest Sciencethe R&D Program for Forest Science Technology (No.2022458B10-2224-0201) of the Korea Forest Service
文摘Pinus densiflora is a pine species native to the Korean peninsula,and seed orchards have supplied mate-rial needed for afforestation in South Korea.Climate vari-ables affecting seed production have not been identified.The purpose of this study was to determine climate variables that influence annual seed production of two seed orchards using multiple linear regression(MLR),elastic net regres-sion(ENR)and partial least square regression(PLSR)mod-els.The PLSR model included 12 climatic variables from 2003 to 2020 and explained 74.3%of the total variation in seed production.It showed better predictive performance(R2=0.662)than the EN(0.516)and the MLR(0.366)mod-els.Among the 12 climatic variables,July temperature two years prior to seed production and July precipitation after one year had the strongest influence on seed production.The time periods indicated by the two variables corresponded to pollen cone initiation and female gametophyte development.The results will be helpful for developing seed collection plans,selecting new orchard sites with favorable climatic conditions,and investigating the relationships between seed production and climatic factors in related pine species.
基金Supported by Undergraduate Innovation and Entrepreneurship Training Program of Guizhou Province(S2024106642161)Zunyi City and Zunyi Normal University Joint Technology Research Fund(ZSKH HZ Z(2023)159)+3 种基金Zunyi Science and Technology Support Program Project(ZSKHZC NS[2023]15)Science and Technology Commissioner Innovation and Entrepreneurship Service Training Demonstration Base of Guizhou Province(HHG2025001)Natural Science Research Project of Department of Education of Guizhou Province(QJJ[2023]043)Zunyi Science and Technology Innovation Team Project(ZKCTD008).
文摘[Objectives]This study was conducted to investigate the impact of soybean intercropping on soil fertility in the planting areas of high-quality peach orchards in Shenxi Town,Zunyi City,Guizhou Province.[Methods]Soil samples were collected during the seedling,growth,and maturity stages of soybeans from both non-intercropped soil(control check group,CK)and soybean-intercropped soil(Qiandou 11,experimental group,EK).Analysis was conducted on soil fertility properties,including alkali-hydrolyzable N,available P,and available K.[Results]The impact of soybean intercropping on soil physicochemical properties was primarily manifested as the increased levels of alkali-hydrolyzable N and available K and the decreased level of available P in the soil during the seedling,growing,and maturity stages.Overall,this approach optimized and enhanced soil fertility in the peach orchards,providing a viable pathway for soil improvement in peach orchards located in karst areas.[Conclusions]The findings of this study provide a scientific basis for the high-quality development of high-quality peach orchards.
基金Supported by Zunyi City-School Joint Science and Technology R&D Fund (ZSKH HZ Z[2023]159)Natural Science Research Project of Guizhou Provincial Department of Education (QJJ[2022]067+3 种基金QJJ[2023]043)Guizhou Provincial Scientific Special Commissioner Innovation and Entrepreneurship Service Training Demonstration Base (HHG2023001)Zunyi Science and Technology Support Program (ZSKHZC NS[2023]15)Science and Technology Cooperation Project of Honghuagang District,Zunyi City (ZHKHSZ[2022]03)。
文摘[Objectives]This study was conducted to clarify the enrichment and paucity of trace elements in the soil environment of peach orchards in Zunyi City,and to provide reference for supplementary application of microelement fertilizers and high-quality peach production in peach orchards.[Methods]Taking the soil of three typical peach orchards(Taoli Renjia peach orchard,Pengrui peach orchard and Taohuadao peach orchard)in Shenxi Town,Honghuagang District,Zunyi City as the research object,the contents of trace elements in soil were analyzed through field sampling and indoor determination of trace elements.[Results]The effective contents of trace elements in the soil of peach orchard bases in the study area were at a medium level,and the soil of the peach orchards was rich in available Fe and Se.The contents of available Cu,Mo and Mn were relatively rich.The contents of available B were not high overall.The contents of available Zn were at a moderate to low level overall.The soil of Taoli Renjia peach orchard was relatively rich in trace elements.[Conclusions]The research results can provide a scientific basis for the production of high-quality crispy peaches in peach orchards.
基金Supported by Science&Technology Support for Xinjiang(201191143)Special Fund for Xinjiang Water Conservancy Science&Technology(2013T04,2013T05)Key Laboratory of Construction Project of Xinjiang Academy of Agricultural Sciences(xjnkkl-2013-001)~~
文摘The aim was to analyze effects of jujube planting years on changes of soil nutrient elements and explore the causes of orchard degradation by researching variation characteristics of soil nutrient contents in orchards with different planting years, providing theoretical support for the soil degradation of jujube or-chards. [Method] Soil samples were col ected in depth at 0-20 and 20-40 cm from the sites in or out of tree canopy scope in jujube orchards with 3, 5 and 7 plan-ning-years, to analyze contents of available N, P and K, organic matter, total N, salts, and trace elements, as wel as changes of nutritional elements. [Result] Avail-able boron, copper, iron, manganese, zinc and available potassium in soils of jujube orchards with 3, 5 and 7 years planting history reduced as planting year increased, which coincided with that in the soil of 20-40 cm. [Conclusion] Because trace ele-ments are never applied in southern Xinjiang, available B, Cu, Fe, Mn, and Zn and available K would be consumed by tree root growth. Due to root distribution differ-ences and ploughing effects in fields, the contents of nutrients tend to be volatile in or out of tree canopy scope. Tree root in deeper soils absorbs more nutrients, and soil nutrients would decrease dramatical y if additional chemical fertilizers are not provided, leading to soil degradation.
基金Supported by Special Fund for Modern Agricultural Industry Technology System(CARS-28)~~
文摘In order to research environment parameters and physiological indices of high-quality and high-yield apple trees, two orchards with young and mature apples trees were investigated to explore structural parameter of apple tree and community, and some physiological indices in fields and by room measurements. The results showed that tree height of high-quality orchard was in the range of 260 to 290 cm, branch angle in 70°-75°, and orchard coverage rate in 75%-94%, and the connec-tion rates between rows and trees were lower. Furthermore, the total branches of mature orchard reached 1.04 ×106 per hm2, while the young orchard was 8.79 ×105 per hm2; the leaves were thick and chlorophyl content was high, with SPAD value at 58.22. Additional y, the photosynthesis of the orchard was strong, and net photo-synthetic rate was 17.48-21.8 μmolCO2/（m2·s）. The proportions of lateral shoot of bearing part were 81% and 75% respectively.
基金Supported by National Key Research&Development Project(2018YFD0800501)Hunan Key Research&Development Project(2016JC2028)Science and Technology Innovation Project in Hunan Academy of Agricultural Sciences(2018QN33)~~
文摘Planting mulch grasses in orchards,as a technique to build ecological orchards,can be one of the strategic approaches for rural revitalization.This study sorted out the common varieties of mulch grasses and analyzed their application statuses in orchards of southern China.According to different utilization purposes of mulch grasses in orchards,scientific suggestions were given from aspects of grass selection,cultivation techniques,management methods and use modes.The study will provide reference for the construction of ecological orchards in southern China.
文摘In the recent years The Mediterranean Fruit fly Ceratitis capitata is distributed in the orchards of central Iraq and caused highly economic losses. This study was conducted in orchards in central Iraq during 2009 and 2010 and made field survey of the insect in four types of orchards （Citrus, Apricot, Figs ＆ Citrus and A mixture of fruit trees） and used for this purpose Tephri Traps supplied with Q-Lure and dimethyl dichloroviny phosphate （DDVP）. The present preliminary study has shown that the Mediterranean fruit fly C. capitata has a year round presence in fruit orchards in central Iraq and reached its highest ntunerical density of the pest in citrus orchards during of November and December were 345 and 363 insect/trap per month in citrus orchards and the least numerical density during of January and February while the highest numerical density of the insect in orchards of Apricot in March 2010, Figs ＆ Citrus in August 2009 and a Mixture of fruit trees in November 2009 were 45, 116, 311 insect/trap per month respectively. The population density of the pest was highest is started 2010 compared with 2009, but the high temperature degree （46-51℃） in August 2010 caused decreasing the population density of this pest. C. capitata caused highly economic losses in citrus reached 68% and 71% of the Mandarin and Kaki fruits respectively Currently in Iraq to fight no control method to reduce the economic losses caused by this pest except the use of pesticides GF-120.
基金Supported by Research and Development Project of Yongning District,Nanning City,Guangxi(20170103B)
文摘Based on the investigation of 56 soil samples( 0-30 cm) in citrus orchards of Guangxi,the content of soil organic matter and available nutrients as well as their correlations in the citrus orchards were studied. The results showed that soil was rich in organic matter,and the proportion of soil samples deficient in available N,P and K was 30. 36%,32. 14% and 28. 57% respectively. Soil was seriously deficient in soil available Ca,Mg and B,while the content of soil available Fe and Cu in soil was too high. There were significant or extremely significant positive or negative correlations between soil pH,organic matter and several available nutrients. It is recommended to apply Mg fertilizer,B fertilizer,lime or other alkaline fertilizer and reduce the spraying of fungicides containing Cu in the citrus orchards.
文摘Black locust （Robinia pseudoacacia L.） is one of the most important stand-forming tree species in Hungary and its impor- tance is increasing in many countries. The main aim of the discussed new selection programme is to identify black locust clones with good performance and good form for setting up clonal seed orchards. As a result of selection programme 16 new black locust clones have been improved. In spring 2002 a black locust seed orchard was established with the newly selected clones. About 40% of the plants can be considered to belong to the height growth rate class 1 and 2. Hungary was the first country where micropropagated black locust planting material was used for seed orchard establishment.
文摘The main objective of this study was to investigate the presence of natural endophytic Beauveria bassiana within date palm tissues using molecular technique and measure their field efficacies in controlling Dubas bug, Ornmatissus lybicus （Deberg）. Two entomopathogenic B. bassiana isolates （MARD 108 and 100） were isolated from date palm, Phoenix dactylifera L. leaves; in addition, one isolate （MARD 92） originally from soil was identified to have endophytic property. Concentration of 1 × 10^9 conidia/mL of each of three endophytic isolates was used in field experiments targeting Dubas bug nymphs via injection tree trunks. The results indicated that the high mortality rates reached 92%, 96% and 100% with infliction of the three endophytic isolates after 15 d from the treatment. The successful establishment of the fungal isolates in the date palm tissue was determined using B. bassiana species-specific primer for the first time via using conventional polymerase chain reaction （PCR） amplification technique before and after injection, and the positive gel band representation was the identification signs. The novel results depicted for the first time the presence of natural endophytic B. bassiana isolates within date palm tissues and their field efficacies in controlling Dubas bug, O. lybicus （Deberg） infestation.
文摘This study to examine soil fertility status was conducted on 10 citrus plantations in Hau Giang province within the Vietnamese Mekong Delta, Vietnam. Fruit trees are mostly grown on the raised beds to avoid annual flood with alluvial soil type. Soil sampling was done in the dry season of 2010 at two soil depths, for each raised bed. Development ages of raised beds were represented by two groups, young age group (≤ 30 years) and old age group (> 30 years). For chemical analysis, pH, organic matter, CEC, total nitrogen, NH4+, NO3– and exchangeable Ca, Mg and K were determined. The results showed that the pH (water) was strongly acid. The CEC was in average 19.2 cmol+.kg–1 in topsoil (0 - 20 cm depth) and 18.7 cmol+.kg–1 in subsoil (20 - 50 cm depth) for young age group. Similarly, the CEC was 16.7 cmol+.kg–1 in topsoil and 15.8 cmol+.kg–1 in subsoil for old age group. Organic matter on young age group (7.38 and 5.47% on average for topsoil and subsoil respectively) was significantly higher than that of old age group (5.20 and 3.81% on average for topsoil and subsoil respectively). Total nitrogen was not significantly different between the sites for the age groups of raised as well as the soil layers. Ammonium-N levels were excessive, and NO3--N levels were high. Potassium and Mg2+ were significantly different between age groups of raised beds and the same pattern between soil layers, while Ca2+ did not vary significantly. Potassium and Ca2+ levels were moderate, Mg2+ was high and P levels were very high. Soil fertility in the raised beds subjected to an adverse on plant growth and an imbalance in soil nutrients under low pH conditions. Loss of soil quality was exhibited in reduced organic matter with the aging of raised beds.
文摘Peach Fruit Fly （PFF） Bactrocera zonata （Saunders） and of the Mediterranean fruit fly （MFF） Ceratitis capitata （Wiedemann） are the most of dominant and destructive key pests in fruit orchards in different agro-ecosystem in Egypt. Population fluctuations of the Mediterranean fruit fly Ceratitis capitata （Wiedemann） and the peach fly Bactrocera zonata （Saunders） was monitored with lure traps collections in three provinces in the New Valley oases, Western Desert, Egypt. Results showed marked temporal differences in peak trap catches of the two flies in the selected sites all over the entire studied areas. One annual peak of C. capitata was recorded during both October and February and coincided with the ripening period of citrus trees in Kharga oases. However, two annual peaks were recorded during June and September in Bodkholow province and coincided with the ripening period of apple and mango. On the other hand, two annual peaks of B. zonata were recorded in Kharga oases throughout May and September and coincided with the ripening periods of apricot, mango and guava. One annual peak only was recorded round up of September and/or October in both of Moot and Bodkholow in Dakhla oases and coincided with the ripening period of mango, guava and citrus. Occurrence of C. capitata was very limited in comparison with B. zonata. Population fluctuations of the two pests in the studied sites were significantly different. The ability of the used traps in capturing both of C. capitata and B. zonata indicated that the yellow sticky trap was more effective in capturing C. capitata. However, Abdel-Kawi trap was significantly efficient in trapping B. zonata. Occurrence of B. zontata in high numbers all over the study period than C. capitata is considered as a good proof that this invading fly may be consider a vigor competitive tephritid fly to the native fly C. capitata.
文摘Automated over-tree sprinkler irrigation systems were developed and tested in two orchards located in two separate locations in southern Iran （a 0.17 ha peach orchard and a 0.24 ha orange orchard） to protect peach blossoms and orange trees leaves and fruits from low temperature damage. The experiment used a system that monitored the trees and air temperatures using two thermistors. The water application rate by the irrigation system was determined by an energy balance as implemented by the software FROSTPRO, In the peach orchard, the system was tested during three frost events during the spring of 2003 and three other events during the spring of 2004. The system successfully kept peach flowers above the critical temperature, i.e., -4.0℃ in spring 2004 （control block -4.12℃, and sprinkled block ＋0.5℃） during all events. Similar results were obtained in the orange orchard during three frost events in the winter of 2004, during which the tree temperatures were at least 2.5℃ above the critical temperature. Results from field tests show that the system can effectively protect the peach blossoms from damage. Determination done after the frost events showed a 12% blossom kill in the sprinkled blocks while in the unsprinkled control block a 41.5% blossom kill. Calculations indicated that when using variable application rates, the amount of water used can be reduced by 54.3%. Spatial distribution of minimum temperatures during the three frosts was also studied in Jahrom, Iran. Results showed a significant temperature control in the experimental block, especially in the central part of the orchard, but the block margins （about 3.6% of the total area） were at the risk of low temperature due to the wind drift effects.
基金supported by the National Natural Science Foundation of China (30370914)the major projects of Zhejiang Province Weather Bureau,China(2006zd005)
文摘We design a weather-based indemnity index for the insurance against freeze damage to citrus orchards so as to provide technological support for the development of policy-based agriculture. The indices are prepared by separating a relative meteorological yield from the yield that is dependent on tree age, high-yield and low-yield years, and environmental factors, and then using a risk assessment scheme to determine the percentage yield reduction due to the meteorological hazard. We thus develop a set of indices associated with cold temperature damage with which to construct more severe weather indices in conjunction with the yield percentage decrease. We then combine the insured regional citrus yield index with the insured meteorological counterpart to obtain a weather-based indemnity index for the varying degree of freeze damage to crops. When the freeze damage index （FDI） is greater than -7.0℃ for the coastal belt of Zhejiang Province, China, or greater than -9.0℃ for other regions of Zhejiang, weather-based indemnity index （WBII） is zero, meaning there is no compensation; when the FDI is from -7.0 to -7.9℃ for the coastal belt or from -9.0 to -9.9℃ for other regions, the WBII is 1 with 50% compensation; when the FDI is from -8.0 to -8.9℃ for the coastal belt or from -10.0 to -10.9℃ for other regions, the WBII is 2 with 70% compensation; and when the FDI is less than -9.0℃ for the coastal belt or less than -11.0℃ for other regions, the WBII is 3 with 90% compensation. The weather indemnity indices of insured orchards are developed in the interest of owners, thereby eliminating adverse selection and moral hazard issues and providing timely recompense from the insurer, and resolving the problem of high indemnity cost in agricultural insurance.
基金Supported by the National Natural Science Foundation of China(Nos.40871115 and 40671095)
文摘Soil samples were collected from apple orchards 5,15,20,30,and 45 years old,and one adjacent forest soil was used as reference to investigate the free Cu2+ion activity in soil solution and the soil Cu fractionation in the solid phase following long-term application of copper fungicide,Bordeaux mixture,in apple orchards and to investigate the relationships among soil free Cu2+ions,Cu fractionation and soil microbial parameters.The total Cu concentration in the orchard soils varied from 21.8 to 141 mg kg-1,increasing with the orchard age,and the value for the reference soil was 12.5 mg kg-1.The free Cu2+ion concentrations in the soil solutions extracted by 0.01 mol L-1 KNO3 ranged from 3.13×10-8(reference)to 4.08×10-6 mol L-1(45 years-old orchard).The concentration of Cu complexed in the fulvic fraction increased with orchard age from 5.16 to 52.5 mg kg-1.This was also the case for other soil Cu fractions except the residual one.The residual soil Cu remained practically constant,ranging from 4.28 to 5.66 mg kg-1,suggesting that anthropogenic soil Cu mainly existed in the more labile active fractions.Regression analyses revealed that both the free Cu2+ions in the soil solution and the humic acid-complexed Cu fraction in the solid phase were strongly related with soil microbial parameters.
基金supported by the Research Fund for the Doctoral Program of Higher Education of China(No.20130101110127)the Project of Zhejiang Key Scientific and Technological Innovation Team(No.2010R50039),China
文摘It is important to understand the effects of temporal changes in microbial communities in the acidic soils of tea orchards with different fertilizers. A field experiment involving organic fertilizer （OF）, chemical fertilizer （CF）, and unfertilized control （CK） treatments was arranged to analyze the temporal changes in the bacterial and archaeal communities at bimonthly intervals based on the 16S ribosomal RNA （rRNA） gene using terminal restriction fragment length polymorphism （T-RFLP） profiling. The abundances of total bacteria, total archaea, and selected functional genes （bacterial and archaeal amoA, bacterial narG, nirK, nirS, and nosZ） were determined by quantitative poly- merase chain reaction （qPCR）. The results indicate that the structures of bacterial and archaeal communities varied significantly with time and fertilization based on changes in the relative abundance of dominant T-RFs. The abundancy of the detected genes changed with time. The total bacteria, total archaea, and archaeal amoA were less abundant in July. The bacterial amoA and denitrifying genes were less abundant in September, except the nirK gene. The OF treatment increased the abundance of the observed genes, while the CF treatment had little influence on them. The soil temperature significantly affected the bacterial and archaeal community structures. The soil moisture was signif- icantly correlated with the abundance of denitrifying genes. Of the soil chemical properties, soil organic carbon was the most important factor and was significantly correlated with the abundance of the detected genes, except the nirK gene. Overall, this study demonstrated the effects of both temporal alteration and organic fertilizer on the structures of mi- crobial communities and the abundance of genes involved in the nitrogen cycle.
基金supported by the National Key Technologies R&D Program of China during the 12th Five-Year Plan period (2012BAD15B04)the National Natural Science Foundation of China (31372137,41671295)+1 种基金jointly supported by the Department for Environment,Food and Rural Affairs (Defra) of UKthe Ministry of Agriculture of China under the Sustainable Agriculture Innovation Network (SAIN)
文摘Excessive nitrogen （N） fertilization of high value horticultural crops is a common problem that not only increases the cost to farmers, but also negatively affects crop growth and the environment. A three-year field experiment was conducted in an intensive kiwifruit orchard in Shaanxi Province, China to compare the effects of reduced N fertilization applied as urea （U）, and controlled release urea （CRU） on the N nutrition of kiwi vines, fruit yield and quality, and nitrate-N accumulation in the soil profile. The three treatments included a conventional N application rate （CF-U, 900 kg N ha-1 yr-1 as urea）, two reduced N fertilization treatments where the amount of N fertilizer applied as U and CRU was reduced by 25％ in 2013 and 2014, and by 45％ in 2015. The 25 and 45％ reduced N treatments had no adverse effects on the N concentrations in leaves and pruning branches and the fruit yield and quality of kiwi vines. However, they significantly enhanced the partial factor productivity of applied N （PFPN） and the economic benefits, and reduced nitrate accumulation in the 0-200 cm soil profile. The same benefits of reduced N fertilization were observed for both the U and CRU treatments, but the CRU treatment had the added benefit of decreasing the loss of nitrate through leaching. We concluded that the current level of N fertilization in kiwi orchards is very excessive, and reducing the N fertilizer rate by 25-45％ could not only guarantee fruit yield, but also reduce N accumulation and loss.
文摘Soil organic carbon and nitrogen are used as indexes of soil quality assessment and sustainable land use management. At the same time, soil C/N ratio is a sensitive indicator of soil quality and for assessing the carbon and nitrogen nutrition balance of soils. We studied the characteristics of soil organic carbon and total nitrogen by investigating a large number of apple orchards in major apple production areas in China. High apple orchard soil organic carbon content was observed in the provinces of Heilongjiang, Xinjiang, and Yunnan, whereas low content was found in the provinces of Shandong, Henan, Hebei, and Shaanxi, with the values ranging between 6.44 and 7.76 g·kg-1. Similar to soil organic carbon, soil total nitrogen content also exhibited obvious differences in the 12 major apple producing provinces. Shandong apple orchard soil had the highest total nitrogen content (1.26 g·kg-1), followed by Beijing (1.23 g·kg-1). No significant difference was noted between these two regions, but their total nitrogen content was significantly higher than the other nine provinces, excluding Yunnan. The soil total nitrogen content for Xinjiang, Heilongjiang, Hebei, Henan, and Gansu was between 0.87 and 1.03 g·kg-1, which was significantly lower than that in Shandong and Beijing, but significantly higher than that in Liaoning, Shanxi, and Shaanxi. Six provinces exhibited apple orchard soil C/N ratio higher than 10, including Heilongjiang (15.42), Xinjiang (13.38), Ningxia (14.45), Liaoning (12.24), Yunnan (11.03), and Gansu (10.63). The soil C/N ratio was below 10 in the remaining six provinces, in which the highest was found in Shaanxi (9.47), followed by Beijing (8.98), Henan (7.99), and Shanxi (7.62), and the lowest was found in Hebei (6.80) and Shandong (6.05). Therefore, the improvement of soil organic carbon should be given more attention to increase the steady growth of soil C/N ratio.
基金Spported by Hubei Public Science and technology Program[Grant No.2013BBB08]Wuhan Science & Technology Planning Project(Grant No.2014020101010075)+1 种基金Special Fund of Hubei Konjak Industry Development in 2013the Natural Science Foundation of China[31401706]
文摘The kiwifruit orchards with plants growing for over two years were chosen for interplanting of konjak, which takes advantages of complementation of the two plants in terms of habits, reducing water and soil erosions effectively, and decreasing water evaporation, and konjak diseases. Furthermore, the interplanting doubles planting benefits and constitutes a highly-efficient planting model.
基金Supported by Science and Technology Program of Fujian Province(2017R1016-4)Natural Science Foundation of Fujian Province(2017J01072)
文摘The Red Soil Hilly Region in South China, where there is a high capacity of carbon(C), and the land use and vegetation cover change greatly, is an important ecological area in the world, and has an important impact on the global carbon cycle and the seasonal fluctuation of atmospheric CO_2. To better evaluate the effects of reclamation systems in orchards converted from grasslands on soil carbon sequestration, we investigated soil organic carbon(SOC) content and stable C isotope(δ^(13)C)composition in three nectarine orchards at Yuchi Experimental Station in South China. Compared with the sloping clean tillage orchard and terraced clean tillage orchard, SOC content in the terraced orchard with grass cover was increased by 14.90% to 38.49%, and 7.40% to 15.33%, respectively. During the 14 years after orchard establishment, the soil organic matter sources influenced both δ^(13)C distribution with depth and carbon replacement. SOC turnover of the upper soil layer in the terraced orchard with grass cover(a mean 63.05% of replacement in the 20 cm after 14 years) was 1.59 and 1.41 times larger than that of the sloping clean tillage orchard and terraced clean tillage orchard under subtropical conditions, respectively. The equilibrium value of soil organic carbon in the three treatments ranged from 16.067 to 25.608 g/kg under the experimental conditions. The equilibrium value of soil organic carbon in the surface layer under grass cover was 54.801 t/hm^2, and the carbon sequestration potential was 24.695 1 t/hm^2.
