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前言影响土壤肥力发挥和施肥效果的因素很多,除作物种类、土壤理化性质、施肥种类、数量、方法和耕作栽培条件外,气温、降水。条件也是一个重要因素。三江平原地区作物生育期5～9月份≥10℃有效积温不但区域间差别悬殊,而且年际变幅也很大,一般在2200℃～2800℃。年降水量350～550毫米,春旱年份较多,秋涝经常出现。由于气温的年际变化和降水
Preface The impact of soil fertility and fertilization effect of many factors, in addition to crop types, soil physical and chemical properties, fertilization types, quantity, methods and cultivation and cultivation conditions, temperature, precipitation. Conditions are also an important factor. Sanjiang Plain crop growth period from May to September ≥ 10 ℃ effective accumulated temperature not only the disparities between regions, and interannual amplitude is also great, usually in the 2200 ℃ ~ 2800 ℃. The annual rainfall of 350 ~ 550 mm, more spring drought years, autumn floods often appear. Due to the inter-annual temperature changes and precipitation