磷肥用量及氮磷钾配合施用对小米草产量的影响

在江汉平原田间条件下研究了磷肥用量及氮、磷、钾肥单施和配合施用对小米草生长及产量的影响.结果表明,在氮钾肥基础上,施磷明显促进小米草株高提高,施磷(P2O5)45,90和135 kg/hm2与不施磷相比产量分别增加23.2%,38.3%和36.3%,分别获得纯利润411.7,624.6和427.9元/hm2,说明施磷明显促进小米草生长,并使产量和经济收益提高,在3个施磷水平中以施磷90 kg/hm2效果最好.不同氮钾肥配合对磷肥效果产生明显的影响,以不施氮、钾肥,仅施氮肥,仅施钾肥和氮、钾肥配合施用为基础,施磷分别提高小米草鲜草产量2 401,5 500,2 051和7 900 kg/hm2,磷与氮钾肥配合施用增产效果最显著.小米草施氮增产效果极显著,其中在磷钾肥基础上施氮的增产效果达1.79倍.在氮、磷肥基础上增施钾肥,增产显著,但若不配合施用氮、磷肥,钾肥施用没有增产效果.在试验条件下,氮、磷、钾肥配合施用对产量具有明显正交互作用,其中氮与磷(在施钾基础上)、氮与磷钾、磷与氮钾的交互值达5 000 kg/hm2以上,说明氮、磷、钾只有配合施用才能充分发挥各种养分的增产作用.

Effect of P application rates and NPK combined fertilization on Echinochloa fru mentacea Yield

A field trial was carried out in Datonghu Administration District of Jianghan Plain to study the response of Echinochloa fru mentacea growth, yield and profit to phosphate application rates and nitrogen (N), phosphate (P), potassium (K) combined fertilization. It was showed that compared to no P treatment, with P_2O_5 rates 45, 90 and 135 (kg/hm~2) the plant height increased by 20.0%, 44.4% and (45.6%), yield increased by 23.2%, 38.3% and 36.3%, and more net profit of 411.7, 624.6 and 427.9 yuan/hm~2 was achieved, respectively. The results indicated that P application significantly promoted Echinochloa fru mentacea growth, yield and benefit, and the best result gained with 90 (kg/hm~2) P_2O_5 rate. The results showed that N and K fertilization had distinct influence on P effect. Based on without N,K, only N, only K and N,K combination, P (at 90 (kg/hm~2) P_2O_5 rate) application improved yield by 2 401, 5 500, 2 051 and 7 900 (kg/hm~2), respectively. N had significant effect on increase Echinochloa fru mentacea yield and N increased yield by 179 percent based on P,K treatment. The results demonstrated that K improved yield significantly based on NP fertilization, however, no effect without N and P combined application. There was positive interaction on yield among N, P and K. The interaction of N and P (based on K application), N and PK combination, and P and N, K combination was over +5000(kg/hm~2). The results displayed that N, P and K combined application could receive the best effect (among) all treatments. It also illustrated that only N, P and K balanced fertilization could each nutrient applied to field take its effect.