缓释复合肥条件下覆盖旱作对水稻氮素利用和稻米品质的影响

Effects of slow-release compound fertilizer and mulched dry-farming on nitrogen use efficiency and quality of rice

水稻旱作和施用缓/控释肥料是提高水肥利用率与减少生态环境污染的重要措施。该文采用田间试验和化学分析方法,比较研究了施用无机缓释复合肥料(ISF)条件下,3种表层管理方式—常规淹水(CF)、地膜旱作(DF)、秸秆覆盖旱作(DS)对冷烂型稻田水稻的生长、叶片氮素形态、氮肥利用率和稻米营养品质的影响。结果表明:水稻植株收获期农艺性状(株高、分蘖势、茎秆重、成穗数和粒重)以DF较好,DF产量较CF和DS分别增加39.1%、41.4%;DF和DS水稻分蘖期和孕穗期叶片NO-3-N含量为CF的2倍以上。水稻分蘖期叶片氨基酸、蛋白氮和全氮含量均为DF>DS>CF。氮肥表观利用率(ARE)、农业利用率(AE)和生理利用率(PE)均以DF>CF>DS。水稻分蘖期叶片的氮素营养状况对稻米氨基酸和蛋白质含量有明显影响,覆膜旱作能提高稻米营养品质。

Rice dry-farming and applying slow-release or controlled-release compound fertilizer could not only improve the use efficiency of water and fertilizer but also abate the environmental pollution. Under the condition of applying the same inorganic slow-release compound fertilizer (ISF), a field experiment was conducted in cold and rotten flooded paddy field to investigate the effects of three different paddy surface managements, i.e. conventional flooding (CF), dryland covered with plastic film (DF) and dryland covered with straw (DS) on the growth characteristics and yield of rice, nitrogen forms in leaf, fertilizer-N use efficiency, contents of amino acid and protein in rice. Results indicated that the rice agronomic characteristics (plant height, tillering capacity, straw weight, number of spike and grain weight) of DF were the best. Compared with the rice yields of CF and DS, the rice yield of DF was increased by 39.1% and 41.4%, respectively. At tillering stage of rice, the contents of amino acid, protein nitrogen and total nitrogen in rice leaf were in the order of DF > DS > CF. However, at tillering and booting stages, the contents of NO3--N for DF and DS were about twice as many as that of CF. The apparent recovery rate and agronomic efficiency and physiological efficiency of nitrogen for rice were in the order of DF>CF>DS. It was indicated clearly that the nitrogen nutrition in rice leaf at tillering stage affected the contents of amino acids and protein in rice and dryland covered with plastic film could improve the quality of rice.