The Wye College Irrigation Game

An irrigation management role-playing game is described. The game aims to provide experience of the problems and complexities of real irrigation management issues, and practice in the application of basic theoretical concepts and methods which are relevant to the successful operation and maintenance of an irrigation scheme. Players acting as farmers or as scheme managers make decisions regarding the operation of a scheme which are processed by micro-computer. Experience shows that the game can achieve its training objectives, stimulates discussion of a wide range of factors affecting the success of irrigation schemes and has the potential for further development.     

加强实践教学 培养高素质农机化人才

实践教学环节是对学生进行综合能力训练、培养学生分析解决实际问题和动手能力和培养高素质人才的重要环节。文章分析了实践教学环节和实践教学建设中存在的问题．针对实践教学中存在的教学方法简单、手段单一、设备老化陈旧等影响学生综合能力锻炼，采取改善教学条件，优化教学要素．采取灵活多样的教学方式，提高学生的综合素质。     

我国东北专用优质商品粮生产基地区域布局研究

运用层次分析法(AHP)对我国东北37个地市农业资源环境进行系统评价,将其结果与37个地市所属各县粮食产量回归分析值进行矩阵运算,确定出东北24县市和1个国有农场总局系统为我国专用优质粮食生产基地。并提出这些专用优质粮食生产基地区域布局建设的对策和建议。     

FARMOD和COSTAB软件在黄土高原水保世行项目中的运用

ＦＡＲＭＯＤ和ＣＯＳＴＡＢ软件在黄土高原水保世行项目中的运用何兴照（黄委会黄河上中游管理局，西安７１００４３）自１９９１年开始准备黄土高原水土保持世行贷款项目以来，几种计算机软件在该项目中的应用，使项目分析工作上升到了一个新层次。本文根据在黄土高原项...     

生物炭和其他有机土壤改良剂对Ustoxic Quartzipsamment土壤上植物养分有效性的影响

A sandy soil, Nampong soil(classified as Ustoxic Quartzipsamment), was incubated under controlled condition i) to compare the mineralization of major plant nutrients derived from different types of biochars and other organic soil amendments; ii) to examine their effects on soil properties and plant nutrient availability; and iii) to evaluate the plant nutrient losses in leachate from the rooting zone of soil incorporated with the different amendments. The experiment was arranged in a completely randomized design with 3 replications.Five treatments of soil amendments used were cassava stem base biochar(CSB), rice husk biochar(RHB), chicken manure(CM),compost(CP), and no amendment application(control). The RHB treatment released the highest amounts of mineralized NO-3-N,available P and K(2.30–17.26, 5.50–42.90 and 43.00–187.63 mg kg-1, respectively) while the CM treatment releasing the highest NH+4-N in the range of 1.86–53.67 mg kg-1. The CSB and RHB treatments showed better continuity of mineralization of nutrients than the treatments of CM and CP, particularly in the case of the CSB treatment. In the soil column incubation experiment, the amounts of NH+4-N and NO-3-N in all treatments barely changed on Day 1 to Day 30 of incubation and then the amounts increased markedly on Day 60. On Day 60, the RHB treatment contained a very high amount of NO-3-N( 250 mg kg-1). This suggests that N would become more available 30 d after the incorporation. The CM treatment gave the highest amounts of organic matter and available P in the ranges of 4.64–8.94 g kg-1and 14.41–36.33 mg kg-1, respectively, during the 60-d column incubation. The CSB treatment tended to have higher available K throughout the measuring period. The NO-3-N was leached from the soil column quite quickly on Day 1 of incubation while the loss of NH+4-N decreased slightly from Day 1 until the end of the measurement. The amounts of P and K losses varied with the type of soil amendments, and the pattern of the loss was irregular.     

Deposition gradients and foliar and soil leachate concentrations of air pollutants in Scots pine stands of S.-E. Finland and the Karelian Isthmus,N.-W. Russia

Bulk precipitation and throughfall analyses in 50–100-year-old Scots pine stands revealed decreasing sulphur, nitrogen, calcium and magnesium deposition gradients, which extend from the St. Petersburg-Leningrad region and N.-E. Estonia to S.-E. Finland. The Ca and Mg deposition alleviate the acidifying effect of sulphur and nitrogen. The Scots pine canopies acted as a sink for ammonium and nitrate, while the canopy interactions increased sulphur, calcium and magnesium content in throughfall. Foliar S, N and Ca concentrations correlated positively with the corresponding deposition loads. In contrast, low foliar magnesium concentrations were detected in the vicinity of St. Petersburg. The results indicate that the sulphur and calcium deposition may have increased soil leachate S and Ca concentrations in the most polluted Scots pine stands.     

Influences of Simulated Acid Rain on the Acidification of Grey-brown Purplish Soil from the Three Gorges Reservoir Region

Column leaching tests were performed to probe the effect of simulated acid rain at different pH values on the acidification of grey-brown purplish soil from the Three Gorges Reservoir Region. The results indicated that the lower the acid rain pH value the more serious the acidification of the soil; the electric conductance of the solution leaching through different soil layers increased at first, then decreased, while the pH value of leachate changed reversely. In general, the higher the pH value and CEC content of the soil were, the greater the electric conductivity of the leachate was. The releasing amount of base ions in four types of typical soils increased with increasing rain acidity, while the leaching amount of aluminium in four types of typical soils increased with the decline of acid rain pH. Changes in the physical and chemical properties of respective soil layers to different degrees were detected after the addition of simulated acid rain of different pH values.     

Application of BP NN for Engine Modeling

The Neural Network(NN) is widely applied to many fields for its unique structure and the method of managing information. The basal concept of the NN and the applied method in the field of engine engineering are introduced. Furthermore, a unique NN structure is also established for the output torque of JL474Q1 engine. It affords the theory base to find the best matching strategy between engine and the transmission system of vehicle.     

Chromosome locations of genes controlling ‘purple leaf base’ in rye and wheat

Summary Purple leaf base is expressed only if there is anthocyanin pigmentation in coleoptiles either in rye or in rye-wheat-additions. Genes controlling purple leaf base were found to be located on chromosomes 5R (An5), 4B (Ra2) and 6B (Ra3) using the trisomic set of rye cv. Esto and autoplasmic rye-wheat-additions, respectively.