| In 2018-2019 in Weining,Guizhou,a two-factor split zone design was adopted to study different film coating methods(wide film,narrow film coverage)and nitrogen application rates(0 kg/ha,80 kg/ha,160 kg/ha,240 kg/ha,320 kg/ha)on soil moisture,temperature and nutrient status of Guizhou spring corn,corn root growth,dry matter and nutrient accumulation,yield and yield traits,clarify the suitable film covering method and nitrogen application of Guizhou spring corn The purpose is to provide reference and guidance for the suitable mulching method of spring corn and reasonable application of nitrogen fertilizer in this area and similar ecological areas.The research results are as follows:1.Under the wide film coverage,the soil water content between the plants at the seedling stage,the jointing stage,the big trumpet stage,the tassel spinning stage and the mature stage was 1.76%,0.92%,1.17%,0.59%,0.80% higher than the narrow film coverage.soil moisture content between rows at seedling stage,big trumpet stage,heading silking stage and mature stage were 2.34%,0.88%,1.40%,2.24% respectively.The results of the two years show that the soil water content of the wide film mulch is higher than that of the narrow film mulch,and the soil moisture content between plants and rows during the whole growth period is 1.08% and 1.35% higher on average.2.In spring maize seedling stage,jointing stage,big trumpet mouth stage,heading silking stage and milk ripening period,the average soil temperature of wide film coverage of 0-25 cm is higher than that of narrow film coverage,and the temperature between plants is 0.05?-0.67? The interval between rows is higher than 0.35?-4.17?.During seedling stage,jointing stage,big trumpet stage and milk maturity stage,the average soil temperature of 0-25 cm inter-plant and inter-row changes reached the maximum at 14 noon,followed by 20 at night;The daily average soil temperature difference between the rows reached the maximum of 0.54-0.80?,2.75-5.50?.3.The content of total nitrogen in 0-20 cm soil covered with wide film was 3.98%-19.28% higher than that covered with narrow film in seedling stage,jointing stage,big bell mouth stage and silking stage of spring maize The content of total nitrogen in 20-40 cm soil covered with wide film was 7.04%,16.43% and 1.61% higher than that covered with narrow film at seedling stage,jointing stage and silking stage.In seedling stage,jointing stage,big bell mouth stage,tasseling stage and mature stage,the content of alkali-hydrolyzed nitrogen in 0-20 cm soil was 9.11%-21.69% higher than that in narrow film mulching.The content of alkali-hydrolyzed nitrogen in 20-40 cm soil at jointing stage,big bell-mouth stage and tasseling stage was higher than that in narrow-film-mulching stage by 7.04%,23.89% and 9.52%,respectively.4.The effects of plastic film mulching,nitrogen application rate and their interaction on the root morphological characteristics of spring maize were significant.The total root length,root length density,root surface area,root volume,root diameter,root tip number and root branch number of maize covered with wide film were significantly higher than those covered with narrow film,which were 19.16%,17.55%,19.20%,8.21%,17.37%,15.11%,respectively,the results showed that wide film mulching could promote the growth of maize root system.When nitrogen application rate was 240kg/ha under wide plastic film Mulching,the root morphological characteristics of maize reached the maximum.5.The effect of plastic film mulching on dry matter and nitrogen accumulation of spring maize was significant.The dry matter accumulation,transportation volume,transportation rate and the contribution rate of dry matter transportation to grain dry matter accumulation in broad-film mulching were 19.50%,54.81%,3.18% and 5.65% higher than that in narrow-film mulching respectively The above-ground nitrogen accumulation,transportation,transportation rate and the contribution rate of nitrogen transportation to grain nitrogen accumulation were all better than that of narrow film mulching,which were 32.35%,40.50%,1.81% and 9.19% higher,respectively.The accumulation of dry matter and nitrogen in the above-ground part was the largest and the difference was significant when the nitrogen application rate was 240 kg/ha under wide film mulching.6.The way of plastic film mulching and the amount of nitrogen applied significantly affected the yield of spring maize.The yield of spring maize covered with wide plastic film was significantly higher than that covered with narrow plastic film,with an average yield increase of 17.79% in two years.The highest yield was 11582.4 kg/ha when nitrogen application was 240 kg/ha(A1N4)under wide film mulching.The number of ears,grain number per ear and 1000-grain weight of wide film mulched maize were better than those of narrow film mulched maize.Through comprehensive analysis of soil moisture,temperature,nutrient status,dry matter,nitrogen accumulation,distribution and transport,root morphological characteristics,yield and other indicators,it was found that wide film mulching improved soil water and heat conditions and nutrient status,and promoted the plant underground Growth,increase the accumulation of dry matter and nitrogen in the aboveground,increase the dry matter and nitrogen transport rate of vegetative organs,and the contribution rate of dry matter and nitrogen transport to the accumulation of grain material,thereby increasing the partial productivity of nitrogen and increasing production the goal of.Under the wide film cover,the appropriate nitrogen application rate is 194.47kg/ha. |
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