Studies On Fertilization Techniques Of Soybean Under Covering Film On Furrow

In accordance with the feature of vigorous growth and needing to supply with macro-elements forinter-rows covered with film, the experiment on ratio, amount and top dressing of N, R K underinter-rows covered with film condition was conducted to study the effect on soybean yield in SuihuaInstitute of Agricultural Sciences from 2005 to 2006.The experiment result of same NPK ratio but different fertilizer amount showed that the yield oftotal NP amount 135kg/hm² was highest, which was 3652.5kg/hm² and was 7.28 percent higher than CK.The NP fertilizer amount had significant effect on root length of different layer and root dry weight.Lower amount fertilizer led the root distributed only on the top layer under film. With the increase ofNP fertilizer amount, the root length and root dry weight in middle and deep layer were increased, andthe total root length and total dry weight were increased either. With the relative increase of NP fertilizeramount, the improved nutrient changed root distribution in soil, which led rot short and wider, noduledevelopment was inhibited that is not suit for uptake water and nutrient from deep soil.The experiment result of same fertilizer amount but different NPK ratio showed that the ratio ofN:P (1:1.5) for control was best, soybean yield was 3420.0kg/hm², the yield of others NPK ratiotreatment was decreased. The yield for treatment with N:P(1:1.7) was 3313kg/hm², which was 3.13percent lower than CK. The ratio of NPK (1:1.5-1.7:0.43-0.46) and total amount of NPK with120-135kg/hm² supplied with seeding got the best yield result. When nitrogen fertilizer was less andphosphorus fertilizer was more at seed sowing stage, the seedling of soybean grew slowly and affectedthe growth and development afterwards. When nitrogen fertilizer was more and phosphorus fertilizerwas less at seed sowing stage, the seedling of soybean grew vigorous and easily caused canopy closureand led to lodging in the later stage.The yield of 9 foliage fertilizers was higher than CK. The yield of once time spraying treatment(urea 10kg plus KH₂PO₄ 1.5kg/hm² and plus B, Mo 0.15kg/hm²) was 15.10 percent higher than CK. Theyield of twice spraying treatment (urea 10kg plus KH₂PO₄ 1.0 kg and plus B, Mo 0.25kg/hm²) was19.17 percent higher than CK.