老梨树"憋劲"修剪法

当老梨树存在着上强下弱、内膛光秃、大小年严重、果品质量等问题时,可采用憋劲法下手修剪(所谓憋劲修剪,就是采用控前促后,堵截养分流向,分年修剪).     

灌溉用水质量的化学评价

本文介绍了灌溉水质参数的计算公式和最主要的化学评价方法。这是作者对国内外自１９３５年以来六十年间有关资料学习、分析、对比和实际使用的小结，可用于生产实际。     

Mechanization of irrigated rice cropping regions in China

The mechanization of rice production in China has experienced a comparatively long and an undulating process. The full-scale making of mechanization of irrigated rice cropping regions was started at the mid 1960's, later than that of upland cropping and its average level of mechanization operation also lower than the average level of the country. During this peiod, however, a series of mechines were created, which adapted to the characteristics of rice cropping regions in China, and the foundation was laid for the later paddy field machinery. For example, transplanting machine (created in 1956), boat—shaped tractors (1961), paddy field ploughing and harrowing serial (1974), and single wheel plowing machines (1979) etc.     

灌溉管理现代化

灌溉现代化以往被看作“工程项目”，即用管道替代开放的沟渠、使用传感器启动灌水铺放导管和平整土地。工程师也参与其中。正如坦桑尼亚一位灌溉专家所说：“我们过去在办公室设计水利项目，将计划保存在办公室。我们认为村民不可能理解这些事情。”     

第三讲 现代地下灌溉机械、设备(二)

①功能用途。能用于小麦、高粱、谷子、油菜等作物条带状的播种及伴随的地下灌水和施肥，适用于干旱地区的土壤底墒较差或由于地形不平、墒情相差很大的情况下，保证播种早出苗、出全苗的精密播种。条播条灌机可一次完成开沟、施肥、播种、覆土、暗注水等作业工序。