磷肥用量对油菜产量、养分吸收及经济效益的影响

Effect of phosphor application rate on rapeseed yield, nutrient absorption and profit

利用大田试验研究了磷肥用量对油菜生长、产量、养分含量、养分积累及经济收益的影响。结果表明,在4个施磷水平下,蕲春和黄冈两个试验点磷肥(P2O5 )用量分别为135kg/hm2 和90kg/hm2 时效果最好,分别提高产量148. 5%和81. 5%,增加纯利润2 532元/hm2 和1 038元/hm2。施磷能大幅度的增加油菜分枝数、每株角果数、每角籽粒数及在一定程度上提高籽粒千粒重。施磷能不同程度地提高油菜各部位N、P、K养分含量,显著地提高油菜地上部对N、P和K的积累量。根据肥料效应方程和油菜籽及磷肥价格确定,蕲春和黄冈试验点最高产量水平时的磷肥用量分别为145. 3kg/hm2 和119. 2kg/hm2,而最佳施磷量则分别为141. 4kg/hm2 和113. 5kg/hm2。

Two field trials with five phosphor (P) application rates of P_2O_5 0, 45, 90, 135 and 180kg/hm^2 were carried out to study the effect of P rate on rapeseed (Brassica napus L.) growth, yield, nutrient absorption and benefit during November 2001 to May 2002 at rapeseed production area in southern-east Hubei Province. The result showed that the best P application rate for Qichun site (soil available P 4.8mg/L, very low) was 135kg/hm^2 and for Huanggang site (soil available P 17.8mg/L, at middle level) was 90kg/hm^2. Based on no P treatment with N 180kg/hm^2, K_2O 120kg/hm^2 and Borax 15kg/hm^2, rapeseed yield increased by 148.5% with the best P rate at Qichun trial and by 81.5% at Huanggang trial. The largest net profit at two sites were 2 532Yuan/hm^2 and (1 038) Yuan/hm^2, respectively. P application significantly increased number of plant branches, siliquae per plant and seeds per siliqua, and also improved 1000-seed weight. It is showed that N, P and K content in different parts of plant increased with P fertilization and nutrient accumulation was greatly increased in up-ground plant parts. According to fertilizer response equations, the highest yield P application rate for Qichun site was 145.3kg/hm^2 and for Huanggang site was 119.2kg/hm^2, and the highest profit P application rate at two sites were 141.4kg/hm^2 and 113.5kg/hm^2, respectively.