Effects Of Organic Materials On Nutrient Uptake And Utilization In Maize And Nitrogen Content In Soil

Since the1950s, the rate of organic fertilizer is decreasing and chemical fertilizer isincreasing. Chemical fertilizer application makes great contributions to increasing foodproduction. But it also brings the questions and threats to the environment and human security.It’s a challenge to solve manure disposal problem with the rapid development of livestockindustry in China. Organic materials retention is an effective way to achieving the fullutilization of the resources. Field plot experiment was conducted to study the spring maize yield,dry matter accumulation, nitrogen uptake and utilization and soil nitrogen transfer andmovement under different N application rates. The main conclusions are as follows:1、Appropriate organic materials could improve maize grain yield under the same Ncondition. As long as control of the returning amount and the proportion of chemical fertilizer，the grain yield of different organic materials would higher than applying chemical fertilizersalone.25%chicken manure+75%chemical fertilizer reached the highest yield and thedifferences were significant with applying chemical fertilizer alone. The results showed thatchicken manure retention could effectively control the release of N which made soil nitrogensupply meet the needs of nitrogen requirement in spring maize, thereby increasing the yield.2、Organic materials on dry matter were higher than no fertilizer treatment under the sameN condition. Organic fertilizer as base fertilizer helped improve the dry matter accumulationand nitrogen application in later stage could increase the phase accumulation of dry matter. It isa crucial time for dry matter accumulation from maize jointing stage to filling stage. It’s veryimportant for dry matter accumulation and yield formation that ensure spring maize get enoughnutrients during that period. The effect of different agriculture wastes retention on dry matteraccumulation is chicken manure>cattle manure>chemical fertilizer alone>straw retention>nofertilizer treatment and dry matter accumulation could be described by Logistic equation. Theresults showed that agriculture wastes retention helped dry matter fast accumulation and dailyaccumulation was advanced，which establishing a substance base for yield formation in maize.3、Different fertilizer treatments had significant effects on N accumulation than nofertilizer treatment under the same N condition. It is3crucial times for N accumulation frommaize jointing stage to big trumpet period，big trumpet period to tassel stage and tassel stage tofilling period. The N accumulation during this period accounted for66.5-73.1%of total Naccumulation. The effect of different agriculture wastes retention on N accumulation is chickenmanure>cattle manure>straw retention>chemical fertilizer alone>no fertilizer treatment. This indicated that agriculture wastes retention could promote spring maize N accumulation andamong those treatments the chicken manure retention was most effective. The highest Nabsorption rates was equal between chicken manure retention and chemical fertilizer alonetreatment, but the yield was higher than other organic materials treatments. Organic andinorganic nitrogen under combined application could delay the daily accumulation.4、The contents of soil total nitrogen has improved after fertilizing. Chicken manureretention had great impact on the contents of soil total nitrogen and then the cattle manureretention and straw retention. Appropriate organic manure/chemical fertilizer ratios couldimprove the contents of soil total nitrogen. Different treatments had less impact on NH4+andthe contents of NH4+at different soil depths were less than4mg/kg. Organic materials had lessimpact on NH4+either. Fertilizers had great impact on NO3-and the contents of NO3-wereincreased with increasing fertilizers. The effect of different agriculture wastes retention on NO3-accumulation is100%chemical fertilizer>25%organic fertilizer+75%chemical fertilizer>50%organic fertilizer+50%chemical fertilizer>75%organic fertilizer+25%chemical fertilizer>nofertilizer treatment, which indicated that excess nitrogen will cause NO3-leaching.