关键词: 养分需求特征, 启动肥, 滴灌施肥, 精准施肥, 秸秆覆盖, 条耕, 追肥机, 玉米

Abstract: To enhance the competitiveness of maize production and to protect the environment, it is necessary to reduce fertilizer input and to increase fertilizer use efficiency in China. Based on maize production in Northeast China, the ways to reduce fertilizer input and to increase fertilizer use efficiency are discussed from the viewpoints of the characteristics of maize nutrient requirements, the fertilizer-saving potential of nutrient-efficient cultivars, the 4R techniques for efficient fertilizer input and the alternative approaches by organic matter applications. To get 100 kg grain yield, the requirement for N, P₂O₅, K₂O in the plant was 1.56-1.89, 0.60-0.88, and 1.27-2.3 kg, respectively. Postsilking N and P uptake is 20%-30% and 20%-40% respectively, which contributes to the grain N and the grain P by 20%-30% and 30%-38%, respectively. At the current soil productivity condition, the N fertilizer requirement for a maize grain yield level of 12 000 kg·hm^-2 is around 180 kg·hm^-2. The application of various new-type fertilizer may save N fertilizer by 9-25 kg·hm^-2. Maize seedling growth can be improved by the application of starter fertilizer Diammonium phosphate and Ammonium sulphate + Calcium superphosphate. A high-clearance fertilizer applicator is required to apply fertilizer at later growth stage so as to match nutrient supply with plant nutrient demand. Fertigation techniques can be used in the sandy soil and/or under drought climate to increase maize yield by 19%-128%, with the highest yield level of 12 000-13 000 kg·hm^-2. Subsurface fertigation has similar effect as the surface fertigation and had a great potential for application. Greenseeker technique can be used to accurately estimate leaf area index, above-ground biomass, and N uptake at maize V5-V8 stage, and therefore to realize precision and variable recommendation of in-season N fertilizer input. Based on the climate and soil conditions in northeast China, various methods can be used to return maize straw residuals to the field so that fertilizer input can be reduced and soil quality is improved. Strip-till technique is expected to be applied greatly in this area because it combines both the advantages of traditional cultivation and no-till. The research in the future should take into account the farmers’ requirement and combines technique development with extension. The researchers should develop applicable technique protocols which target the specific cultivation and/or planting patterns and can be used in a large area now or in the future, so as to reduce fertilizer input and increase fertilizer efficiency in a regional level.

Key words: nutrient demand characteristics, starter fertilizer, fertigation, precision fertilization, straw mulching, strip-till, fertilizer applicator, maize