西北干旱灌区紫花苜蓿高产田施肥效应及推荐施肥量研究

Fertilization effect of alfalfa high yield field and its recommended fertilizer application in northwest drought irrigated area

为揭示紫花苜蓿氮、磷、钾肥效应,采用“3414”不完全正交回归设计,对紫花苜蓿氮、磷、钾肥合理配比施肥效应进行研究,同时对紫花苜蓿产量及蛋白总量进行肥效模型拟合。结果表明,氮、磷、钾对建植2年苜蓿产量的贡献为钾>磷>氮,对建植3年苜蓿产量的贡献为磷>钾>氮,建植2与3年苜蓿交互效应均表现为氮磷>氮钾>磷钾。氮、磷、钾对建植2年苜蓿蛋白总量的贡献为氮>钾>磷,对建植3年苜蓿蛋白总量的贡献为氮>磷>钾。建植2年苜蓿氮磷肥互作效应明显优于氮钾、磷钾互作;建植3年苜蓿氮磷、氮钾交互对苜蓿蛋白总量的增产效果明显大于磷钾交互。采用频度分析法,通过模拟寻优,得出建植2年紫花苜蓿目标产量大于平均产量17522kg·hm^-2时,优化施肥量为氮56.27~67.51kg·hm^-2、磷77.69~90.48kg·hm^-2、钾76.43~87.18kg·hm^-2;建植3年紫花苜蓿目标产量大于平均产量19234.1kg·hm^-2时,优化施肥量为氮46.75~57.66kg·hm^-2、磷80.15~92.28kg·hm^-2、钾57.79~69.74kg·hm^-2;建植2年紫花苜蓿目标蛋白总量大于平均2115kg·hm^-2时,优化施肥量为氮66.35~77.48kg·hm^-2、磷79.34~92.87kg·hm^-2、钾73.68~85.38kg·hm^-2;建植3年紫花苜蓿目标蛋白总量大于平均2656kg·hm^-2时,优化施肥量为氮68.44~79.50kg·hm^-2、磷72.74~85.96kg·hm^-2、钾50.68~61.61kg·hm^-2。

The comparative importance of nitrogen,phosphorus and potassium fertilizer addition in alfalfa forage production,was studied using an incomplete orthogonal regression design.The forage yield and total protein yield of alfalfa were included in a fertilizer effect model in this study.It was found that the contribution of N,P and K to the yield of a two year old alfalfa stand was K>P>N,and the contribution to the yield of three year old alfalfa was P>K>N,while the interaction effect in two and three year old alfalfa stands ranked N-P>N-K>P-K.For total protein yield the corresponding rankings were N>K>P,and N>P>K,respectively,for two and three year old alfalfa stands,indicating that nitrogen is the key limiting factor in alfalfa protein production.For total protein yield,the N-P interaction and the N-K interaction effects were significantly greater than that of the P-K interaction.By using the frequency analysis method,the optimal fertilization amounts of N,P and K were calculated as 56.27-67.51 kg·ha^-1,77.69-90.48 kg·ha^-1 and 76.43-87.18 kg·ha^-1,respectively,when the target dry matter(DM)yield of two year old alfalfa is higher than 17522 kg·ha^-1;as 46.75-57.66 kg·ha^-1,80.15-92.28 kg·ha^-1 and 57.79-69.74 kg·ha^-1,respectively,when the target DM yield of three year old alfalfa is higher than 19234 kg·ha^-1;as 66.35-77.48 kg·ha^-1,79.34-98.87 kg·ha-1 and 73.68-85.38 kg·ha^-1,respectively,when the target total protein yield of two year old alfalfa is higher than 2116 kg·ha^-1;and 68.44-79.50 kg·ha^-1,72.74-85.96 kg·ha^-1 and 50.68-61.61 kg·ha^-1,respectively,when the target total protein yield of three year old alfalfa is higher than 2656 kg·ha^-1.