A Study On The Fertilizing Techniques For Direct-seeding Oil Rape Under Zero Tillage Condition

The experiment of fertilizing technique of direct-seeding oil rape under the zero tillage condition was conducted in Shimen county in 2002-2003. The purpose of this experiment was to exploit: (1) the effects of different fertilizer method on the agronomic and economic characters and the yield of oil rape; (2) the applicable possibility of slowly-releasing compound fertilizer coated with polymer membrane; (3) the optimum formula and application amount of coated compound fertilizer and (4) the fertilizing method for direct-seeding oil rape under the zero tillage condition. The results were mainly summarized as follows:The different fertilizing treatments had some effects on the growth procedures of oil rape. The growth and development was ahead of time and the growth duration became shorter under the no fertilizer treatment.According to the observation for the emergence and senescence of the 7-14th leaf of oil rape, the duration from one leaf emergence to next leaf emergence increased 0.5-0.7d in average compared with no fertilizer treatment (CK|). The function duration per leaf elongated 5-7d in average compared with CK1. The average function duration of per leaf of treat A (traditional fertilizer method) and treat B (compound fertilizer) was 3.5d and 1.5d less than that of treat c (coated compound fertilizer). The leaf emergence duration between two leaves treat F|, F2, F3, F4 (coated compound fertilizer, plots in turn 30, 40, 50, 60kg/667m2) each was 0,2-0.4d longer that that of CK2(no fertilizer treat), as well as the function duration per leaf increased 3-6d in the fertilizing treatments. The leaf function duration delayed with the increase in fertilizing rate.Fertilizing treatments affected the growth at seedlings and at mid-late stage of oil rape. Compared with CK|, the seedlings of treat A, B, C increased 0.2-1.2 green leaves, 0.0-2.8 cm diameter of root-stem and 3.6-362.4 cm2 leaf area per plant, of which the best seedling quality was observed in treat C. With the increase in fertilizer rate applied, the green leaves, the length of the largest leaf, the diameter of root-stem and leaf area per plant showed a small increased to some extent. Compared with F|, F4 increased 2.3 green leaves, 1.7 cm leaf length and 1.8 cm leaf width of the largest leaf, 2.7 cm diameter of root-stein and 942.9 cm2 leaf area per plant. In the range of 30-60kg/mu applied coated-compound fertilizer the vegetative growth and biomass increased with the increase of fertilizing rate. The tendency of plant growth before winter was similar to that after spring. As a result, it is beneficial to yield formation.Fertilizing treatment obviously affected the number of primary branches, effective pods of main fluoresce, effective branches and the number of effective pods per plant. But no significant difference of plant height, grains per pod and 1000-grain weight was observed between different fertilizing treatments except for the main fluoresce of treat C. As for the different fertilizing method, treat C increased 3.2-10.4 (by 7.5-29%) effective pods of main fluoresce as well as 11.3-28 (by 12.9-40.8%) effective pods of branches compared with treat A, B and CK1.There were no differences of grain yield among three fertilizing methods, but their yield was significantly higher than that of no-fertilizer plot (CK1). The grain yield of treat C was up to 93.3kg/667m2 and 41.1kg/667m2 (by 81.9%) higher than that of plot (CK1). In the range of 30-60kg/667m applied coated-compound fertilizer, the yields increased with the increase in fertilizer applied and that of plot F4, F3, F2 and F1 was 105.8,99.6,90.9, 74.5kg/mu respectively.