301. Effects of precipitation and nitrogen on spring corn yield in black soil regions.

• Authors:
  • Wen, Y.
  • Gong, Z.
  • Gu, S.
  • Lu, J.
  • Zhao, J.
• Source: Transactions of the Chinese Society of Agricultural Engineering
• Volume: 27
• Issue: 12
• Year: 2011
• Summary: The objective of this study was to distinguish effects of main growing factors on the corn yield under dry-farming conditions. A corn field experiment with three factors and four levels for each factor was conducted using the same corn cultivar and the same design in three consecutive years on a black soil classified as typic udolls of which the available nitrogen is middle but both available phosphorus and potassium are high. The results showed that, the most limiting factors to corn yield were respectively precipitation in growing season (PGS), rate of nitrogen fertilizer and available nitrogen contents of soil. Only when the PGS was greater than 280 mm, was nitrogen fertilizer effect statistically noticeable. The appropriate combination of nitrogen, phosphorus and potassium fertilizers increased the water use efficiency by 24.3% compared to no fertilizer treatment. Corn yield was positively correlated with the available nitrogen contents of soil too, meaning that higher soil available nitrogen contents are favorable to the increase in corn yield.

302. Dynamic of phosphorus with wheat-soybean rotation systems under conservation tillage in the western Loess Plateau.

• Authors:
  • Shen, Y.
  • Wang, X.
  • Zheng, L.
• Source: Acta Prataculturae Sinica
• Volume: 20
• Issue: 4
• Year: 2011
• Summary: The research presented crop yield, phosphorus dynamic for a wheat-soybean rotation systems affected by tillage management: conventional tillage (t), tillage+ stubble retention (ts), no-till (nt), no-till+stubble retention (nts) in the Loess Plateau. Results showed that ten years tillage management implementation did not carry a yield penalty for winter wheat, soybean yield had a positive response to conservation tillage. Soil phosphorus content increased with the increasing of rotation sequences. Both total phosphorus and available phosphorus contents were increased at top 0-5 cm. Stubble retention increase crop phosphorus uptake, P contents in soybean grain under nts and ts treatment were 111% and 82% higher than that under t treatment. The results provide a local agricultural implement provides certain theoretical guidance.

303. Research situation and prospect of maize rough dwarf disease.

• Authors:
  • He, K.
  • Wang, Z.
  • Li, W.
  • Huang, Q.
• Source: Journal of Maize Sciences
• Volume: 19
• Issue: 2
• Year: 2011
• Summary: Research history and the current status of maize ( Zea mays) rough dwarf disease (MRDD) were reviewed with respect to distribution, symptoms, pathogen, host range, transmission path, and varietal resistance to MRDD. Rice black streaked dwarf virus (RBSDV), maize rough dwarf virus (MRDV) and Mal de Rio Cuarto virus (MRCV) are all causative agents of MRDD around the world. RBSDV is the causative agent of MRDD in China. Small brown planthopper ( Laodelphax striatellus) was the vector of RBSDV. Crop interplanting, especially wheat intercropping with a maize cropping pattern, was closely related to the MRDD, which provided suitable habitat and a recurrent host for L. striatellus and RBSDV. Resistant germplasms have been lacking, and the application and prevention of technology did not meet the demands for managing MRDD until now. Coordinating the relationship between the high-effect planting model (interplanting) and disease prevention, developing simple, practical and high-effect control measures including the innovation of maize germplams resistant to the disease, are the problems needing to be solved in production.

304. Study on ecological effect and physiological characteristics in apricot and wheat intercropping systems.

• Authors:
  • Nuermaimaiti, T.
  • Zhang, X.
  • Zhao, Q.
  • Gao, Y.
  • Sailihan, S.
  • Qiao, X.
  • Chen, X.
  • Lei, J.
• Source: Xinjiang Agricultural Sciences
• Volume: 47
• Issue: 12
• Year: 2011
• Summary: Objective: The present study was set to discuss ecological effects and physiological characteristics of wheat of apricot and wheat intercropping system. Method: The area from Apricot base point to the middle of two rows of apricot trees are divided into three areas: area under the crown, area near crown, area far away from crown. Study on changes in physiological characteristics of ecological indicators in the apricot and wheat intercropping in wind speed, soil temperature, chlorophyll content. Result: The colser from the distance of the apricot, the lower soil water content in wheat field; The wind speed, plant nutrients in apricot and wheat intercropping field are less than that in wheat monoculture field. Soil temperature under 5 cm for the apricot and wheat intercropping system are less than that in wheat monoculture field before 14:00; soil temperature under 5 cm of wheat monoculture field are higher than that of apricot and wheat intercropping system after 14:00. Wheat booting stage is the obvious contradiction of competition for water between wheat and apricot. Compared with different crown area in intercropping system, the area far away from crown demands for more chlorophyll content of wheat. Compared with wheat monoculture field and intercropping system, there was a fight for nutrient between wheat plants and apricot trees in intercropping field. The efficiency of uptaking nutrient of wheat plants was much lower than that of apricot trees nutrient content of less. Conclusion: Under apricot tree and wheat plant intercropping conditions, the closer from the distance of apricot trees, the less the soil moisture content, the less chlorophyll content of wheat plant. The physiological characteristics of wheat in monoculture field were superior to that in intercropping field.

305. Crop nitrogen use and soil mineral nitrogen accumulation under different crop combinations and patterns of strip intercropping in northwest China.

• Authors:
  • Zhang, F.
  • An, M.
  • Christie, P.
  • Sun, J.
  • Yu, C.
  • Li, Y.
  • Li, C.
  • Li, L.
• Source: Plant and Soil
• Volume: 342
• Issue: 1/2
• Year: 2011
• Summary: Increasing crop nitrogen use efficiency while also simultaneously decreasing nitrogen accumulation in the soil would be key steps in controlling nitrogen pollution from agricultural systems. Long-term field experiments were started in 2003 to study the effects of intercropping on crop N use and soil mineral N accumulation in wheat ( Triticum aestivum L. cv 2014)/maize ( Zea mays L. cv Shendan16), wheat/faba bean ( Vicia faba L. cv Lincan No. 5) and maize/faba bean intercropping and monocropping systems. Monocropping was compared with two types of strip intercropping: continuous intercropping (two crops intercropped continuously on the same strips of land every year) and rotational intercropping (two crops grown adjacently and rotated to the other crop's strip every year). Maize/faba bean intercropping had greater crop N uptake than did wheat/faba bean or wheat/maize. Wheat/maize accumulated more mineral N in the top 140 cm of the soil profile during the co-growth stage from maize emergence to maturity of wheat or faba bean. Continuously intercropped maize substantially decreased soil mineral N accumulation under wheat and faba bean rows (60-100 cm soil depth) at maize harvest. Soil mineral N accumulation under wheat rows increased with rotational intercropping with faba bean. Rotational intercropping may potentially alleviate the adverse effects of wheat on N use by other crops and increase the nitrogen harvest index of wheat, maize and faba bean. Intercropping using species with different maturity dates may be more effective in increasing crop N use efficiency and decreasing soil mineral N accumulation.

306. Overyielding and interspecific interactions mediated by nitrogen fertilization in strip intercropping of maize with faba bean, wheat and barley.

• Authors:
  • Li, L.
  • Zhang, F.
  • Christie, P.
  • Wei, X.
  • Sun, J.
  • Li, Q.
• Source: Plant and Soil
• Volume: 339
• Issue: 1/2
• Year: 2011
• Summary: Interspecific interactions and soil nitrogen supply levels affect intercropping productivity. We hypothesized that interspecific competition can be alleviated by increasing N application rate and yield advantage can be obtained in competitive systems. A field experiment was conducted in Wuwei, Gansu province in 2007 and 2008 to study intercropping of faba bean/maize, wheat/maize, barley/maize and the corresponding monocultures of faba bean ( Vicia faba L.), wheat ( Triticum aestivum L.), barley ( Hordeum vulgare L.) and maize ( Zea mays L.) with N application rates of 0, 75, 150, 225 and 300 kg N ha -1. Total land equivalent ratios (TLER) were 1.22 for faba bean/maize, 1.16 for wheat/maize, and 1.13 for barley/maize intercropping over the 2-year study period. Maize was overyielding when intercropped with faba bean, but underyielding when intercropped with wheat or barley according to partial land equivalent ratios (PLER) based on grain yields of individual crops in intercropping and sole cropping. There was an interspecific facilitation between intercropped faba bean and maize, and interspecific competition between maize and either wheat or barley. The underyielding of maize was higher when intercropped with barley than with wheat. Fertilizer N alleviated competitive interactions in intercrops with adequate fertilizer N at 225 kg ha -1. Yield advantage of intercropping can be acquired with adequate nitrogen supply, even in an intensive competitive system such as barley/maize intercropping. This is important when using intercropping to develop intensive farming systems with high inputs and high outputs.

307. The formation of kernel number per spike and analysis of yield components of wheat under shade condition.

• Authors:
  • Zhou, Y.
  • Zhang, X.
  • Chen, X.
  • Zhao, Q.
  • Lei, J.
  • Zhang, H.
  • Qiao, X.
• Source: Xinjiang Agricultural Sciences
• Volume: 48
• Issue: 10
• Year: 2011
• Summary: Objective: The purpose of this project was to clarify shade condition's effect on the formation of kernel number per spike and analyze yield components of wheat under shade condition so as to take an effective growth measurement on fruit tree-crop intercropping models (Jujube-wheat, Apricot-wheat and Walnut-wheat intercropping). Method: In the present paper, the effects of shading on kernel number per spike were studied and analysis of yield components of wheat under the artificial shade condition was carried out. Result: The results showed that, under the artificial shade condition, the fertile florets, plant weight, grains per spike, grains weight per spike, spike number per hectare and yield were obviously reduced in the course of the wheat growth period. Conclusion: The results indicated that improving the kernel number per spike should be focused on the differentiation, growth and development, degeneration and grain courses of florets. Improving the yield should be focused on the growth and development, spike number per hectare and grain-filling characteristic courses of plants.

308. Water use efficiency of winter wheat in ridge cultured wheat||spinach-tomato cropping system.

• Authors:
  • Liu, M.
  • Zhai, H.
  • Shi, C.
  • Dong, B.
  • Ruan, F.
  • Qiao, Y.
• Source: Chinese Journal of Eco-Agriculture
• Volume: 19
• Issue: 5
• Year: 2011
• Summary: Ridge planting and intercropping of winter wheat ( Triticum aestivum L.) are important cropping systems in the North China Plain (NCP), in which there exists an acute shortage of water resources especially for crop production. This study analyzed water use efficiency ( WUE) of winter wheat in wheat||spinach-tomato cropping system using both traditional and ridge cultivation as the control practices. Traditional cultivated spinach ( Spinacia oleracea L.) and tomato ( Lycopersicon esculentum Miller) system was the control cropping practice for the spinach||tomato intercropping system. The results showed that wheat grain yield under ridge planting and intercropping was 11% less than under traditional cultivation (401 kg.667 m -2). The reduction in grain yield was attributed to low tiller number as ridge-edge effect was not fully exploited. Tiller numbers of ridge-planted ridge-intercropped wheat were 13.2% and 8.2% less than traditional cultivated wheat system. Row tiller number was much less in either ridge-planted or ridge-intercropped systems than in traditional cultivation system. Comparisons among the three cropping systems suggested that traditional wheat cropping had the highest WUE (1.039 kg.667 m -2.mm -1), and that intercropping had the lowest WUE (0.868 kg 667 m -2.mm -1). Ridge cultivation had a smaller WUE (0.944 kg.666.7 m -2.mm -1) than traditional cultivation system because between-ridge water was not fully utilized. Yield of spinach was, however, not affected by wheat. Yields of intercropped and traditional cultivation spinach systems were 826 kg.667 m -2 and 851 kg.667 m -2, respectively, with a difference not statistically significant. However, tomato growth was greatly hampered under the intercropping system. Stem diameter and biomass per plant under intercropped tomato was respectively 27% and 37% less than that under traditional cultivation system. This suggested that after spinach harvest, tomato transplanting should be postponed as long as possible so as to shorten crop symbiosis and make the cropping system more manageable. It was therefore concluded that wheat||spinach-tomato cropping system facilitated di-season vegetable and food production, provided that the wheat and vegetable cultivars were properly selected and cultivated.

309. Spatial distribution characteristics of root system of jujube trees in jujube-wheat intercropping system.

• Authors:
  • Taxi, Z.
  • Song, F.
  • Yishake, H.
  • Yu, T.
  • Shi, Y.
• Source: Journal of Northeast Forestry University
• Volume: 39
• Issue: 10
• Year: 2011
• Summary: A study was conducted to discuss the spatial distribution of root system of jujube trees in jujube-crop intercropping system in Aksu by the layered digging method, in order to provide a theoretical basis for the establishment of root water uptake model for jujube trees, the analysis of ecological characteristics of water, and the determination of application area. Results showed that, in the vertical direction, in the jujube-wheat intercropping system, the jujube roots distributed in the 0-80 cm soil layer, accounting for 82.55% of root biomass and 74.87% of root length density, while in the jujube-cotton intercropping system, the jujube roots distributed in the 0-90 cm soil layer, accounting for 82.66% of root biomass and 66.75% of root length density; in the horizontal direction, in the jujube-wheat intercropping system, the jujube roots distributed in 0-100 cm away from the jujube tree, accounting for 82.10% of root biomass and 56.99% of root length density, while in the jujube-cotton intercropping system, the jujube roots distributed in 0-150 cm away from the jujube tree, accounting for 81.46% of root biomass and 83.80% of root length density. The distribution regularity of root length density of different root diameter classes and total root length density was consistent. Roots of 0- to 1.0-mm root diameter class mainly distributed in the 0-80 cm soil layer and 0-150 cm away from the jujube tree, and the root length density decreased with increasing soil depth and distance from the tree (horizontal direction). Regression equations explaining the relationships between total root length density or total root biomass and the horizontal distance from the tree and soil depth were established.

310. Study on the soil temperature characteristics in early spring under apricot-wheat system in the south of Xinjiang.

• Authors:
  • Fu, L.
  • Jia, Q.
  • Yang, L.
  • Fan, D.
  • Zhang, P.
  • Lu, C.
  • Wang, F,
• Source: Xinjiang Agricultural Sciences
• Volume: 48
• Issue: 8
• Year: 2011
• Summary: Objective: According to the measured data of soil temperature and air temperature in early spring in Kashgar area of Xinjiang, the temperature change characteristic about apricot wheat interplanting and the only wheat monoculture during the 24 h was analyzed. Method: The paper took Saimaiti apricot of 8 years old and Xindong-20 as investigative objects, and carried out a study of phenophase, horizontal distance, soil depth and air temperatures at different levels under the intercrop and monoculture model by ZDR-41. Result: The results showed that: (1) the total changes of soil temperature present the onefold type of "S"; (2) there were differences in the sustained time of temperature extremum under the 20 cm soil layer of different modes. The topmost and lowermost of air temperature did not have sustained time, but it had sustained time of the topmost and lowermost under the different horizontal distance in the intercrop model; (3) in the stages in germination, temperature under monoculture model was higher than intercrop model at the same soil depth. The average temperature of the stages in apricot germination was monoculture > the distance of 2 m to stem of apricot > the distance of 1 m to stem of apricot > air temperature. Conclusion: In the stages in germination of early spring, apricot orchard inter-crop wheat have definite effect to reduce soil temperature. The time change and the soil temperature were gradually ascended. In the period of apricot bloom, the horizontal distance at different levels did not have obvious effect on soil temperature.