Organic Manure Staging Record Cotton 2250kg/ha High-yield Effect And Mechanism Of Fertilizer

This study was carried out in the 揇emonstration Zone of Cotton Science and Technology of Jiangsu Province?from 1997 to 1999. Four kinds of fertilizer treatments were arranged in field plots: (a) all of the organic manure (cai~,osted chicken faeces) were applied before transplanting (Cl); (b) one half of organic timnure was applied before transplanting and another half was applied at the flowering stage (C2); (c) all of the organic manure were applied at the flowering stage (C3); and (d) only chemical fertilizers were applied (as control). The application rates of fertilizers in 1998 and 1999 were 592. 5kg N/ha and 600kg N/ha, in which organic N accounted for 2.4% and 10.0%, respectively. The ratio of N:P206:K20 in the organic and inorganic fertilizers applied was approximately 1:0.5:0. 58. The cotton cultivar was Sumian 8 and the seedlings were transplanted at a density of 4. 95x104 plants/ha The results were as follows: (1) Organic manure was effective in improving soil fertility. Soil organic matter conent increased by 0.37g/kg, soil bulk density decreased by 0.02g/cn? and soil porosity increased by 0.84% annually. (2) Responses of cotton yield to organic manure were more obvious with the lasting of years. Lint yield in the second and third year was significantly increased in the plots received organic manure. (3) In whole growth season, the cotton reaching 2250kg/ha lint yield absorbed 325.0kg N/ha, 73. 9kg P2O~/ha and 284.0kg I(20/he, and the ratio of N:P205:K20 was 1:0.23:0.89. 60 61 (4) CS treatment showed positive effect for preventing the over- growth of cotton at the earlier stage and the rapid decline at the later stage. (5) In C2 treatment, the duration of fertilizer efficiency went on synchronously with the course of cotton growth, and the peak of nutrient supply was in the pace of massive formation of buds and boils. (6) In C2 treatment, the intensity of boll formation, boll numbers, total boll setting rate, highuality boll setting rate, boll weight, lint percentage and seed cotton rate were increased in comparison with Cl and CS treatments. The tempopatial distribution of boll setting was also better in C2 treatment than other treatments. (7) Larger leaf area index (maximum LAI was 5. 0), longer period of leaf area peak (as long as 42 days), and better spatial distribution of leaf layers were observed in C2 treatment. (8) The biological production (aboveground biomass) of cotton exceeded 15 t/ha in C2 treatment in 1998, in which the productive organs accounted for 56. 1%.