施肥方式对小麦生长、产量及土壤硝态氮含量的影响

摘要

采用田间小区试验的方法,研究了5种施肥方式(处理1:1/2尿素播种前撒施旋耕,1/2尿素返青拔节期追施旋耕;处理2:全部尿素播种前撒施旋耕;处理3:全部控释氮肥播种前撒施旋耕;处理4:全部控释氮肥播种前在种子正下方条施;处理5:全部控释氮肥播种前在种子侧下方条施)对小麦生长、产量及土壤硝态氮含量的影响.结果表明,各处理间小麦株高、穗粒数和千粒质量差异不显著,基本苗数和冬前最大分蘖数以处理2最高,春季最大分蘖数以处理1、3、5较高,3个处理间差异不显著.处理1、3、4、5的小麦生物量较高,处理间差异不显著,但均显著高于处理2.小麦产量受穗数影响最大,处理1、3、5的产量较高,分别为9 139、9 097、8 930 kg/hm2,三者差异不显著;处理2产量最低,为8 407 kg/hm2,显著低于其余4个处理.氮肥偏生产力各处理间变化趋势与产量一致,处理1、3、5较高,彼此间无显著差异,处理2最低.处理3、4、5在拔节期和孕穗期0~90 cm土层硝态氮含量与施用尿素的处理1、2差异相对较小(60~90 cm孕穗期差异相对稍大),在小麦收获后硝态氮含量相对较高.总体上,控释氮肥一次性撒施旋耕和条施于种子侧下方的施肥方式效果较好,既能保证小麦稳产,又能使土壤保持较高的硝态氮含量,从而减轻面源污染的风险.%The effects of five fertilization modes(treatment 1: 1/2 urea broadcasting before sowing,1/2 urea broadcasting at root elongation stage;treatment 2: all urea broadcasting before sowing;treatment 3: all controlled release nitrogen fertilizer broadcasting before sowing;treatment 4:all controlled release nitrogen fertilizer banding blow the seed directly before sowing;treatment 5:all controlled release nitrogen fertilizer banding blow the seed on one side before sowing) on wheat growth,yield and soil content of nitrate nitrogen were studied using field plot test method.The results showed that wheat plant height,spike grain number and thousand seed weight had no significant differences among five treatments.Treatment 2 had the highest basic seedlings and winter maximum tillering.Treatments 1,3 and 5 had higher spring maximum tillering,and there was no significant difference among the three treatments.Wheat biomass of treatments 1,3,4 and 5 were significantly higher than that of treatment 2,but there was no significant difference among the four treatments.The wheat yield was most affected by spike number.Treatments 1,3 and 5 had higher wheat yield,with 9 139 kg/ha,9 097 kg/ha and 8 930 kg/ha,respectively,and there was no significant difference among them.The wheat yield of treatment 2 was the lowest with 8 407 kg/ha,and was significantly lower than that of the other four treatments.The change trend of nitrogen partial productivity among the five treatments was in accordance with that of wheat yield,which were that treatments 1,3 and 5 had higher nitrogen partial productivity and yield,and there was no significant difference between each other,treatment 2 had the lowest values.The difference of nitrate nitrogen content at wheat jointing stage and booting stage between the three controlled release nitrogen fertilizer application treatments 3,4,5 and the two urea application treatment 1,2 was small 0-90 cm soil,and relative big in 60-90 cm soil.Soil nitrate nitrogen content of treatments 3,4 and 5 was relatively higher after harvest.In general,the fertilization modes of controlled release fertilizer one-time broadcasting and banding blow the seed on one side had relatively better effect,which could not only guarantee the wheat yield,but also keep the high content of nitrate nitrogen in soil,so as to reduce the risk of non-point source pollution.