青贮玉米对氮磷钾的吸收规律

Nitrogen,Phosphorus and Potassium Absorption in Ensilage Maize

以粮用玉米、粮饲兼用玉米和青贮专用玉米为材料,研究了植株氮、磷、钾营养的含量、吸收、积累及平衡吸收关系。结果表明,青贮品种植株氮、磷含量变化与粮用品种不同,其全生育期含氮量变化为单峰曲线,峰值出现在出苗后55d,含磷量较平稳,含钾量呈降低趋势。青贮玉米需氮、磷、钾量比粮用和粮饲兼用玉米高,且更应重视钾肥的投入。青贮玉米适宜的N∶P2O5∶K2O=2.74±0.14∶1∶5.94±0.82,每生产100 kg干物质所需要的氮、磷、钾量分别为(0.57±0.05)kg、(0.26±0.03)kg和(1.58±0.12)kg。

There have been many reports about the requirements of nitrogen, phosphorus and potassium in grain maize ,but seldom in ensilage maize. The objectives of this research were to compare the N, P, K requirements among grain maize, grain-forage maize and ensilage maize, and to provide a guide of fertilizer application for high yielding and high effective cultivation of ensilage maize. The N, P2O5 and K2O contents absorption and accumulation amounts and absorption ratio in the plants were measured and the results showed that nitrogen and phosphorus contents in ensilage maize were different from that in grain maize. The nitrogen contents of ensilage maize showed a unimodal curve during the growing stage, and reached the maximum at 55 d after seedling emergence. The phosphorus contents were relatively stable, and the potassium contents decreased gradually in the process of growth. The ensilage maize required more nitrogen, phosphorus and especially more potassium than grain-forage maize.The suitable fertilization ration was N： P2O5 ：K2O = （2.74 ± 0.14） ： 1 ： （5.94 ± 0.82） ,and the demands for N, P2O5 and K20 per 100 kg dry matter produced were （0.57 ± 0.05 ） kg, （ 0.26 ± 0.03） kg and （ 1.58 ± 0.12）kg,respectively. The demand of N and P205 per 100 kg dry matter was grain maize cultivar 〉 grain-forage maize cultivar 〉 ensilage maize cuhivar, and that of K2O was ensilage maize cultivar 〉 grain-forage maize cultivar 〉 grain maize cultivar. It indicates that ensilage maize has higher dry matter production efficency.