紫色土区作物耐氯临界值类型的研究

STUDIES ON CRITICAL VALUES OF CROP TOLERANCE TO CI IN PURPLE SOILS

用五种紫色土和15种作物,以施N、P、K为对照,设8级施氯水平(0～3200ppm)进行盆栽试验。根据作物产量、品质与对照等产等值的原则,将作物耐氯力划分为强、中、弱三种类型,并确定其植株及土壤的耐氯临界值和求出作物产量与施氯水平的曲线回归方程,以指导含氯化肥应用,较传流施肥更为科学。

Thirty pot experiments with five purple soils and fifteen crops were carried out in which 8 Cl levels in the range of O-3200pm were adopted in addition to N, P and K. Based on the data of grain yield and quality, the crops studied were grouped into three types: high, intermediate and low Cl-tolerant. The high CI-tolerant crops included rice, ba rley, cotton, etc. and showed high tolerance to CI^-. They were able to tolerate CI^- concentrations as high as 600-1000 ppm. The CI^- contents of 0.5-1.5% in the shoot at seedling stage or 0.4-0.8 at maturation stage had no adverse effects on grain yield and qualty. wheat, oilseed rape, radish and some others proved to be of intermediate tolerant type and did well at 400-600 ppm of CI^-, 0.6-1.4% of CI^- in the shoot or 0.05-0.09% of CI^- in the seed showed no adverse influence on grain yield and quality. Letture, sweet potato, broad bean, garden pea were identified as low CI-tolerant crops, for they could only tolerate CI^- concentrations below 400 ppm. However, 0.6-3% of CI^- in the shoot and 0.03-0.06% in the seed did not adversely affect the yield or quality of the crop.