Study On The Effect Of Starter Fertilizer On Increasing Yield Of Maize

Objective:Starter fertilizer is a small amount of fertilizer applied at the seed at about 5 cm below×5 cm beside of the seed and significantly promote the early growth of maize.Maize production is mainly drip-irrigated in Xinjiang.Farmers generally not apply base fertilizer in this cultivation system,but all fertilizers are topdressing by drip irrigation.Generally,the first irrigation of maize is carried out at around 50 days after the maize emergence,combining with topdressing,so the nutrition of maize seedlings completely depends on soil nutrients in its seedling stage.Therefore,starter fertilizer is critical for maize at seedling stage.Maize is a thermophilic crop and is vulnerable to low temperature stress,resulting in weak uptake ability of root system and poor aboveground growth.However,cold wave in spring is common in Xinjing.At the same time,the availability and mobility of soil phosphorus are low due to low soil temperature,resulting in serious impact on maize growth.This experiment studied the enhancement effects of starter fertilizer combined with bioactive substances on the effect of starter fertilizer,and the effects of different soil temperatures and soil phosphorus levels on the growth and development,nutrient uptake and yield of maize.So as to provide a theoretical basis for the fertilization method of starter fertilizer and the efficient utilization of nutrients in drip-irrigated maize production in Xinjiang.Methods:（1）A field experiment was set up in 2020-2021 at Tianye Agricultural Experiment Station（44°21′N,86°04′E）in Shihezi,Xinjiang to study the effect of combining bioactive substances with starter fertilizer on the performance of starter fertilizer.The test maize variety Xinyu65（Zea mays L,cv,Xinyu65）.Five treatments were set up:no phosphate fertilizer（CK）during the whole growth stage,farmers’conventional fertilizer（CF）,drip-irrigated diammonium as starter fertilizer（DSF）,humic acid with drip-irrigated diammonium as starter fertilizer（HSF）,and citric acid with drip-irrigated diammonium as starter fertilizer（CSF）.All there treatments received identical N,P₂O₅and K₂O nutrients besides the CK treatment.（2）The pot experiment was carried out at the Experimental Station of the Agricultural College of Shihezi University（44°31′N,86°05′E）in 2021.The effect of starter fertilizer on the growth of drip-irrigated maize under different soil temperature was tested,and two factor experiments were set up.Factor one was soil temperature,which was set at low temperature（LT,15.0℃）,medium temperature（MT,20.7℃）and high temperature（HT,25.4℃）.The second factor was the starter fertilizer treatment:with（SF）or without starter fertilizer（CF）respectively.There were six treatments,and received identical N,P₂O₅and K₂O nutrients.（3）The pot experiment was carried out at the Experimental Station of the Agricultural College of Shihezi University（44°31′N,86°05′E）in 2021.A two factors experiment was conducted to study the effect of starter fertilizer on the growth of drip-irrigated maize under different soil phosphorus levels.Factor one was the soil’s phosphorus level,which was three levels of low phosphorus（LP,2.47 mg/kg）,medium phosphorus（MP,12.35 mg/kg）and high phosphorus（HP,33.67 mg/kg）.The second factor was the starter fertilizer:with（SF）or without starter fertilizer（NS）,respectively.There were six treatments.Results:（1）The promotion effects of starter fertilizer combined with bioactive substances on total root length,root length density and root weight density in drip-irrigated maize showed HSF≈CSF>DSF>CF in 2020and 2021.DSF,HSF and CSF treatment increased yield by 4.60%,8.77%and 9.82%in 2020 and 4.64%,10.63%and 11.99%in 2021 compared to CF treatment,respectively.The order of in-season phosphorus recovery rate,phosphorus agronomic use efficiency and phosphorus partial factor productivity for each treatment was HSF≈CSF>DSF>CF.Compared to DSF,the economic benefits of HSF increased by1275 CNY/hm² and 2039 CNY/hm²in 2020 and 2021,and the economic benefits of CSF increased by 1709CNY/hm² and 2596 CNY/hm² in 2020 and 2021,respectively.（2）Under the LT,MT and HT,the total root length of maize treated with SF increased by 15.47%,13.43%and 14.77%at the jointing stage,and at the maturity stage dry matter accumulation increased by16.60%,13.13%and 9.23%,the N accumulation increased by 7.60%-10.68%,the P accumulation increased by 9.12%-17.40%,the K accumulation increased by 7.61%-16.38%,and,the bald tip length of maize decreased by 27.60%,55.01%and 55.24%,and the yield increased by 11.62%,10.53%and 8.44%respectively.（3）Under LP level,the adventitious roots number,primary root length,total root length of seed root,total root length of adventitious root,unit adventitious root length and root dry matter weight of maize were significantly lower than those of MP and HP,but these root parameters had no significant difference between MP and HP.At the LP level,the adventitious root numbers,total root length and root dry matter weight of SF treatment were significantly greater than those of NS treatment.At the MP level,the total root length of adventitious root and root dry matter weight of SF treatment significantly greater than those of NS treatment.At the HP level,there was no significant difference in root and shoot growth indicators between SF and CF treatments.At LP and MP levels,the plant height,stem diameter,leaf number,leaf area,leaf SPAD value,net photosynthetic rate,root dry matter weight and phosphorus uptake of SF treatment were greater than those of NS treatment.Conclusion:The application of starter fertilizer combined with humic acid or citric acid can significantly promote the root growth of maize at seedling stage,enhance the nutrient absorption capacity of root system and improve the yield.Therefore,it is a better fertilization technology to improve the utilization efficiency of phosphorus fertilizer and increase the economic benefit of maize.The effect of starter fertilizer on promoting the growth and yield of maize under low temperature is better than that in medium and high temperature.The application of starter fertilizer on soil low and medium phosphorus levels has an significant promoting effect on maize growth and phosphorus uptake comparing with soil high phosphorus level.