不同滴灌施肥量对沙地玉米氮效率及硝态氮的影响

Effects of different fertilization by drip irrigation on nitrogen efficiency and nitrate nitrogen in sandy land

探索沙地春玉米最佳滴灌施肥方案是提高其生育期氮积累和氮效率的有效途径。试验采用三因素D饱和最优设计,研究拔节期、抽雄期和收获期玉米产量、生育期植株不同器官氮积累和硝态氮含量的差异,结果表明:(1)随着玉米生育期推进,整株氮积累逐渐增加,叶片、茎下降,籽粒增加,高氮处理(氮肥240 kg·hm^2)显著高于其他处理;(2)N_3P_1K_3处理产量最高(13 875 kg·hm^2),氮素转运量和营养器官贡献率显著高于其它处理,氮收获指数和氮肥偏生产力较低;(3)土壤硝态氮含量随植株生长吸收逐渐降低,以滴头处0~20 cm硝态氮含量最高,20~60 cm逐渐降低;(4)不同施氮处理的硝态氮含量有差异,拔节期施肥处理均与CK差异显著,抽雄期和收获期中氮处理和高氮处理对硝态氮影响显著。高氮处理中土壤0~60 cm硝态氮含量与播前基本一致,维持了土壤硝态氮的平衡。综合考虑产量、氮效率及土壤硝态氮平衡方面的因素,膜下滴灌条件下,陕北风沙滩地玉米合理的施肥为N_3P_1K_3处理,即施氮肥240 kg·hm^2,磷肥80 kg·hm^2,钾肥225 kg·hm^2。

It is an effective way to improve nitrogen accumulation of maize and nitrogen use efficiency by exploring the optimum drip irrigation and fertilization scheme.In this paper,maize yield,nitrogen use efficiency and nitrate nitrogen content of different organs were studied in jointing stage,tasseling stage and harvest stage by using the three-factor D-saturated optimal design.The results showed:(1)With the maize growth,the nitrogen accumulation of the whole plant and grain increased gradually,while that of the leaves and stems decreased.The nitrogen accumulation in the high nitrogen treatment,which applied with N 240 kg·hm-2 nitrogen fertilizer,was significantly higher than the other treatments;(2)The maize yield of N3P1K3 treatment was the highest(13875 kg·hm^-2),nitrogen transport and vegetative organ contribution rate were significantly higher than other treatments,and nitrogen harvest index and nitrogen fertilizer partial productivity were lower;(3)The soil nitrate nitrogen content decreased gradually with the growth of the plant.The nitrate content of 0~20 cm depth at the dripper was the highest,and it decreased gradually in 20~60 cm depth;(4)The contents of nitrate nitrogen in different nitrogen treatments were different,and the fertilization treatment at jointing stage was significantly different from CK.Nitrogen treatment and high nitrogen treatment had significant effects on nitrate nitrogen during tasseling and harvesting stages.The content of soil nitrate nitrogen in 0~60 cm depth for the high nitrogen treatment was basically the same as that before sowing,and the balance of soil nitrate nitrogen was maintained.Considering the factors of yield,nitrogen efficiency and soil nitrate nitrogen balance,under the condition of drip irrigation under the film,the reasonable fertilization of maize in the sandy land of northern Shaanxi is treated with N3P1K3 treatment,namely,nitrogen fertilizer 240 kg·hm^-2,phosphate fertilizer 80 kg·hm^-2,and potassium fertilizer 225 kg·hm^-2.