Study On The Effects Of Fertilizer And Organic Manure On The Biomass And Nitrate Contents In The Leafy Vegetables

The effect of mineral nutrition and organic manure on the biomass and nitrate content in the leafy vegetables were studied in this paper with the combination of pot experiment and field experiment. The results were as follows.The experiment of the soil nutrition limiting factors showed that the biomass of rape in the treatments of-N (PKMoZnB) and -P (NKMoZnB) accounted for 36.6% and 52.6% of the treatment of NPKMoZnB respectively. The treatment of -Mo (NPKZnB) accounted for 84.6% of the treatment of NPKMoZnB. The biomass of rape was no significant difference in the treatments of -K, -Zn, -B, 1/2N, 1/2P, 1/2K compared with the treatment of NPKMoZnB. The nitrogen fertilizer was the most important factor influencing the nitrate content in the leafy vegetables. The nitrate content in the treatment of-N, 1/2N decreased by 94.4%,54.9% compared with that in the treatment of +N. The nitrate content of the rape was no significant difference in the treatments of-K, -Zn, -B, 1/2N, 1/2P, 1/2K compared with the treatment of NPKMoZnB.The applying amount of nitrogen fertilizer and phosphate fertilizer influenced the biomass and the nitrate content of rape.The results showed that the biomass of rapes increased in +N treatments compared with -N treatment. When nitrogen fertilizer (N) was applied at 196.6kg/hm2, the biomass of rape was the highest in all the N treatments. With the increasing of nitrogen fertilizer, the nitrate content increased, and there was a striking correlation between the amount of nitrogen fertilizer and the nitrate content. The biomass of rape increased by using phosphate fertilizer. When phosphate fertilizer (P2O5) was applied at 160.6kg/hm2, the biomass of rape was the highest in the P treatments. There was no obvious change in the nitrate content in different P treatment.The biomass and the nitrate of rape were affected by the doses of N fertilizer and the different manure. The results showed that the biomass of rape increased with applying the decomposed manure accompanying with the low doses of nitrogen fertilizer. The nitrate content did not change considerably. The biomass of rape decreased by applying thesemi-decomposed manure and the none-decomposed manure accompanying with low doses of nitrogen fertilizer, the nitrate content decreased. When the doses of nitrogen fertilizer was 300kg/hm2, there was no obvious difference in the biomass and the nitrate content by applying the decomposed manure, but the biomass of rape increased and the nitrate content decreased applying the semi-decomposed manure and the none-decomposed manure. Under the higher doses of the nitrogen fertilizer(600kg/hm2,900kg/hm2), the biomass of rape increased and the nitrate content did not change strikingly by applying the decomposed manure, semi-decomposed manure and none-decomposed manure.There was no significant effect on soil EC and NO3- by applying the different manure accompanying with low doses of nitrogen fertilizer. Soil EC and NO3- increased by applying the decomposed manure accompanying with high doses of nitrogen fertilizer. But Soil EC and NO3- decreased by applying the semi-decomposed manure and none-decomposed manure accompanying with high doses of nitrogen fertilizer.When the doses of nitrogen fertilizer was 300kg/hm2 and the decomposed manure was used, the biomass of rape was highest compared with the treatment of using N (300kg/hm2); the nitrate content did not change considerably. When the doses of nitrogen fertilizer was 600kg/hm2 and semi-decomposed manure or the none-decomposed manure was used, the biomass of rape was highest compared with the treatment of using N(600kg/hm2); the nitrate content did not change strikingly.The yield and nitrate content of Chinese cabbage were influenced by using nitrogen fertilizer accompanying with the decomposed manure. The results showed that the yield and nitrate of Chinese cabbage increased by using N fertilizer. It was no difference with using N fertilizer and decomposed manure comparing with using N fertilizer.