Strategy of balanced fertilization on leafy vegetables

• Main Authors: Chong-Sheng Wang, 王重勝
• Other Authors: Jen-Hshuan Chen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/63555019446635079003

碩士 === 國立中興大學 === 土壤環境科學系 === 92 === ABSTRACT Nutrients release and contribution of organic and chemical fertilizers to soils and crops were found different, it included economic, effective and safe profits that planed a balanced fertilization strategy to satisfy the requirements of crops by applying organic fertilizers with chemical ones. The objectives of this research were to detect the nitrogen (N) and phosphorus (P) release of animal compost applied in soils as a function of time, to plan the balanced fertilization strategy by using organic and chemical fertilizers together, and to evaluate the effects of chemical, organic, and four chemical with organic treatments on soils and crops by planting cabbages in pots and water spinaches in the field. Laboratory incubation experiment was conducted with different added amounts of animal composts, ureas, and superphosphates, and the results were figured as a function of time for replacing or net replacing chemical fertilizers by organic ones. The recommended N-P-K amounts were regarded as the application amounts for the chemical fertilizer treatments, and eight treatments were established: (i) check (CK): unfertilized check; (ii) chemical fertilizers (CF): fertilized check; (iii) animal compost I (N50): the applied amounts of animal compost were estimated according to the N requirement of crops and the N release rate at 50%; (iv) animal compost Ⅱ(P30): the applied amounts of animal compost were estimated according to the P requirement of crops and the P release rate at 30%; (v) animal compost with chemical fertilizers I (N50F): the applied amounts of animal compost were equal to N50 treatment, and chemical fertilizers were added to reach the recommended N-P-K amounts; (vi) animal compost with chemical fertilizers Ⅱ (P30F): the applied amounts of animal compost were equal to P30 treatment, and chemical fertilizers were added to reach the recommended N-P-K amounts; (vii) animal compost with chemical fertilizers Ⅲ (BF1): the applied amounts of animal compost were estimated according to the P requirement of crops and the P release rate at 30%, and chemical fertilizers were added to reach the recommended N-P-K amounts by calculating the N and P release amounts with net replacing figures; (viii) animal compost with chemical fertilizers Ⅳ (BF2): the applied amounts of animal compost were estimated according to the P requirement of crops and the P release rate at 30%, and chemical fertilizers were added to reach the recommended N-P-K amounts by calculating the N and P release amounts with net replacing figures, while the recommended amounts were increased or decreased according to the soil fertility. Pot cabbage experiment were conducted with eight treatments and field water spinach experiment were with six treatments (CK, CF, N50, P30, P30F, and BF2). The results of incubation experiments showed that the N and P release rate of animal compost applied in Tali soil after 20 weeks were 42% and 22%, respectively. Because of the different growing periods, organic fertilizer treatments resulted in higher yields and N uptake the chemical ones in planting cabbages, while chemical fertilizer treatment was better in planting water spinaches. Animal compost application based on N needs for two crops both resulted in soil accumulation of P and soluble salts, however, application based on P needs both resulted in deficient N. Applying additional N as fertilizer, could improve the N deficiency, and lower the soil accumulation of soluble salts and P. In addition, the balanced fertilization treatment that adjust the recommended N-P-K amounts according to soil fertility, could reinforce the improvement on yields and N uptake, however, it couldn’t arise the negative effect together. Thus, summing up the results from cabbage and water spinach experiments, BF2 treatment was recommended as the balanced fertilization strategy for leafy vegetables.