黄绵土营养诊断与双低油菜平衡施肥研究

采用温室盆栽与田间试验研究甘肃省高寒阴湿区黄绵土养分状况。结果表明,盆栽诊断黄绵土缺N、P、S和Zn,未表现缺B、Cu和Mn,Fe和Mo元素充足,N、P肥为大田该黄绵土种植油菜的主要限制因子,其次为S、B和Zn,土壤中不缺K,OPT中氮量适中。与OPT相比,减N、P、S、B和Zn油菜分别减产24.5%、27.1%、13.5%、16.8%和8.8%,而增加N用量则产量降低12.2%。推荐施肥N、P2O5、S、B、Zn分别为90、90、105、3.75、3.75kg·hm-2。盆栽诊断与大田平衡施肥间有很好的相关性,可用来指导大田试验。

Nutrition Diagnosis of Loessal Soil and Balancing Fertilizer of the Double low Rapeseed

In this paper, with the pot experiment and field experiment, the status of nutrients of Loessal soil at chilling and humid region of high elevation in Gansu Province is studied. The results show that the limiting nutrients of Loessal soil are the deficiency of N, P, S and Zn, the soil has no deficiency of B,Cu and Mn, enough amount Fe and Mo. In field experiment, the main limiting nutrients are N and P fertilizers, secondly are S, B and Zn, the soil has enough amount K, OPT are suitable of N. Based on the treatment of OPT. Non application of N, P, S, B and Zn fertilizers can reduce the yield of the double low rapeseed prominently and the decreasing amplitudes are 24.5%, 27.1%, 13.5%, 16.8% and 8.8% respectively. While increasing the N application decreases the yield and the decreasing amplitude is 12.2%. The recommendatory fertilizer dosage of loessal soil is N 90 kg·hm^-2, P₂O₅ 90 kg·hm^-2, S 105 kg·hm^-2, B 3.75 kg·hm^-2 and Zn 3.75 kg·hm^-2 respectively. There is a good correlation between potted diagnosis and field experiment, and it can be used to guide field trials.