江西棉区棉花氮肥与密度互作效应续试总结

Further Study on the Interaction Effect of Nitrogen Fertilizer and Density in Jiangxi Cotton Region

在江西棉区油棉双移栽种植制度、沙质壤土和中等生产力水平条件下,于2008～2010年连续3年设置不施含氮肥(ck)、施无机态氮150、300、450、600 kg/hm2和施有机与无机态氮搭配300 kg/hm26个处理,进行氮肥经济高效施用技术定位试验,在此基础上,再于2011～2012年插入当地生产上常规密度和当地生产条件下杂交棉密度试验最佳密度的两个代表密度进行氮肥与密度互作试验。结果表明:两年的试验结果基本相似,一是施氮对棉花生育期略有影响,而密度对生育无明显影响;二是随着施氮水平的提高,其株高、单株成铃数、单位面积成铃总数、果枝数、单铃重均相应增加,单株果枝数略有减少,但密度增加株高变化不明显,单株成铃数和单铃重降低;三是子棉产量均以高施氮水平和高密度较好,随着施氮量增加子棉产量显著增加,随着密度增加子棉产量略增加;四是施氮处理产值均明显高于不施氮处理,且以施氮量增加产值略增加;五是不施氮处理的效益出现较大的负值,其他处理有较小的效益;六是氮增效以低氮处理大,且随着施氮量增加而逐渐降低;七是综合产值、效益与氮增效等指标认为,适宜施氮水平为300～450 kg/hm2,种植密度为34500株/hm2左右。

Under the conditions of rape and cotton double transplanting system, sandy loam and medium conditions of productivity, 6 treatments which were without application of nitrogenous fertilizer （CK）, inorganic nitrogen 150, 300, 450, 600 kg/hmz and application of organic and inorganic nitrogen witb300kg/hm2 respectively were set for nitrogen fertilizer high ef- ficiency application localization testing in northern Jiangxl cotton region from 2008 to 2010. On this basis, from 2011 to 2012,two representative densities which were optimal for hybrid cotton and conventional cotton cultivation respectively were used to carry out nitrogen fertilizer and density interaction test. The results showed that： 1. nitrogen had slight influence on cotton growth period, and the density had no significant effect on growth; 2. the plant height, boll number per plant, total boll num- ber per unit area, the number of fruit branch, boll weight were all increased with the increase of nitrogen application. With the increase of the density, plant height did not change significantly, boll number per plant and boll weight both decreased; 3. the seed cotton yield of high nitrogen level and high density were both better, the seed cotton yield increased significantly with the increase of nitrogen, the seed cotton yield slightly increased with the increase of density; 4. compared with CK, the output val- ue of nitrogen application treatments were all significantly higher, and output value increased slightly with the increase of nitro- gen; 5.earnings of no nitrogen treatment were negative value, the other treatments had smaller earnings; 6.nitrogen fertilizer could increase efficiency significantly within low nitrogen application level, and with the increase of nitrogen application amount gradually, incremental efficiency were slight; 7. the optimum nitrogen level was 300 - 450 kg/hm2, the optimal plant- ing density was about 34500 plants/hm2.