广州地区甜玉米测土配方施肥指标体系研究

Research on index system for sweet maize fertilization by soil testing in Guangzhou

在对广州地区土壤养分状况进行调查的基础上,通过系统的"3414"试验,建立了相对产量与土壤养分回归方程,从宏观上评价了广州地区甜玉米主产区土壤养分丰缺指标,初步建立了甜玉米施肥指标体系。通过对萝岗、番禺、增城、南沙4个试验点的甜玉米产量与施肥量进行回归分析,建立氮、磷、钾三元二次肥料效应函数:Y=727.83+15.13N-0.28P+11.70K-0.28N2+9.025P2-0.19K2-0.16NP+0.01NK-0.13PK(R2=0.91)。对该回归方程进行显著性检验,P<0.05,表明氮磷钾肥施用量与产量有显著的回归关系,结合单、双因素分析结果,推荐广州地区甜玉米理论每667 m2产1 000 kg的氮、磷、钾肥最佳施肥量约为24、7、19 kg。施肥经济效益分析表明,氮、钾肥的收益在一定范围内与施肥量成正比,磷肥施用量过高会出现负收益现象。施肥经济效应分析结果与三因素效应方程分析结果一致。

Based on a wide range of soil investigation in Guangzhou,this study evaluated macro soil nutrient status in main sweet maize production area by carrying out systemic ＂3414＂ fertilizer experiments and preliminarily formulated fertilization index for sweet maize,laying foundation for effectively increasing yield by fertilizing.By means of regression analysis between yield of sweet maize and fertilizer amount from Luogang,Panyu,Zengcheng and Nansha areas,ternary quadratic function of NPK fertilizer were established.It was described as Y=727.83＋15.13N-0.28P＋11.70K-0.28N2＋9.025P2-0.19K2-0.16NP＋0.01NK-0.13PK（R2=0.91）.The significance test of the regression equation（P0.05） revealed an remarkable relationship between them,combined with results from single and double indicator analysis,the optimal fertilizer amount of NPK were 24,7 and 19 kg respectively for the yield of 1 000 kg per 667 m2 in Guangzhou region.Consistent with three-factor formula,the study of economic benefit from fertilizing indicated that profits were increasing with growing application of NK fertilizers within some extent while decreasing when excessive P fertilizer was supplied.