Studjes On Influence Of Zinc Fertilizers On The Absorption And Cumulatioil Of Zinc Content And The Regulatory Mechanism Of Zinc Availability

Zn is an essential trace element for plant growth, animals and humans. And human Zn deficiency is quite serious worldwide. About40%of the population in the world is facing a lack of trace elements. Zn mainly migrates in the form of food chain constituted by soil(environment)-plants(animals)-food-human.However, amount of zinc in the agricultural products cannot meet people’s health demand. Zn deficiency problem has not been fundamentally resolved yet.Nowadays zinc deficiency is still a worldwide problem affecting human health. As one of the three major grain crops, corn plays an important role in people’s life.And corn is also one of crops which are sensitive to Zn, Zn deficiency in soil will affect the growth and development of corn directly,resulting in poor yield and decreased quality. Hence how to improve the Zn content of crop kernels has drawn much attention.To solve the Zn deficiency, the effective measurements should be taken, for example,Improving soil Zn deficiency symptoms,and increasing edible content of zinc in food crops to make up for the deficiencies of Zn intake. Applying Zn fertilizer is the most direct and effective way to improve the Zn content of corn.This study focuses on the effective in aeolian sandy soil and black soil,Zn supplement by different application way and Zn fertilizer application:studying the changes of corn rhizosphere soil Zn content as well as various forms of Zn using root confinement method;Improving the efficient use of Zn by reducing the pH activated soil Zn artificially in soil little intra-area by laboratory simulation study and adding acid ball in field soil;studying availability of Zn using different P,Zn ratio during corn seedling.The main results of this paper are as follows:1.With three application way (Soil application of zinc fertilizer, foliar Zn spraying,soil application of Zn fertilizer+foliar spray Zn) in field experiment in aeolian sandy soils, the influence of Zn fertilizer on corn yield and quality was investigated.Plant and grain zinc content increased significantly in above three experiments (comparing with the non-application of Zn) in different corn growth stages of the corn.Zn content peaked during corn seedling, and Zn content increases with the growth of plants,dry matter accumulation above ground and the total cumulative amount of zinc until maturity.Both dry matter accumulation above ground and the Zn accumulation are largest in the experiment of combining soil application of Zn fertilizer with foliar spray Zn in different growth period.The general trend of Zn absorption rate increases firstly and then decreases above ground in various growing stages,in other words,the Zn absorption rate is the lowest during seedling stage-jointing stage,highest during jointing stage-silking stage,and has a reducing trend during silking stage-filling stage and filling stage-maturity.The yield of maize, which increases by6.8%to12.9%,is tallest using soil application of Zn fertilizer+foliar spray method in three experiments.2.The influence of Zn application on corn yield and quality is studied in field experiment with normal (10kg/hm2、25kg/hm2ZnSO47H2O) and ultra-high (10kg/hm2、25kg/hm2ZnSO47H2O) Zn application in aeolian sandy soil and black soil. Plant and grain zinc content in the growing stages of the corn has an increasing trend as the increasing Zn application in both soils. However, all the experiments shows Zn content in black soil is higher than Aeolian sandy soil, which have maximum at the seedling stage and minimum at the maturity; Zn accumulation in corn plants increases with the plant growth with the fixed Zn application, and it has a significantly positive correlation with dry matter accumulation; Zn content of corn grain embryo, endosperm, pericarp and hypocotyls has also an increasing trend as the application of increase Zn content in black soil,The Zn content of the various parts is different and the relation is the embryo>peel≈hypocotyl> endosperm.The optimal Zn application related to yield is50kg/hm2.3.The experiment of absorbing soil Zn2+is studied under low molecular weight organic acids (citric acid(citric acid, oxalic acid, succinic acid, malic acid, and acetic acid) and P conce-ntration (0、30、60、120mg/L).The results show that the absorption capacity among five low molecular weight organic acids on Zn2+is ordered as followed:acetic acid<citric cid<oxalic acid≈malic acid<succinic acid; the sequence with four kinds of P content is P120>P60>P30>P0; higher P content has a benefit of improving the maximum absorption capacity, the buffer capacity, and the absorption capacity of soil on Zn2+4.The influence of different P (37.5,75,150kg/hm2),Zn (25,50,100,150kg/hm2) ratio on P-Zn relation at seedling stage through pot experiment in aeolian sandy soils is studied. The results demonstrate:available phosphorus content of plants and soil decreases with the increase of Zn fertilizer application. But available phosphorus content of plants and soil increases with the increase of P fertilizer application when the Zn fertilizer application is fixed.On the contrary, available Zn content increases with the increase of Zn fertilizer application when they have the same P fertilizer application,available zinc content decreases with the increase of P fertilizer application when the Zn fertilizer application is fixed.This suggests that P,Zn in soil and corn plant have antagonism effect.5.To research on variation znic content amount of different Zn fertilizer (0、15、30、45kg/hm2) in rhizosphere and nonrhizosphere of corn root confinement technique in Aeolian sandy soil is adopted.The amount, surface area and length of roots in root bags show an increasing tendency as the amount of Zn application grows, as well as Zn content and the plants in roots. When Zn application is different as to upper and lower layer of rhizosphere soil and nonhizosphere soil Ex-Zn, CARB-Zn, OM-Zn, MnO-Zn,CFeOX-Zn,it ranks as non-hizosphere soil>upper rhizosphere soil>lower rhizosphere soil,while as to AFeo-Zn,upper rhizosphere soil>lower rhizosphere soil>nonhizosphere soil;when Zn application is the same,in order of Zn content, the rank is CFeOX-Zn>AFeO-Zn>CARB-Zn>Ex-Zn>OM-Zn>MnO-Zn.6.The simulation root Zn different levels soil Zn activation process study are conducted using concentrated sulphuric acid carbonized corn stover and different proportions of clay.The results show that the different of pH content increased from inlayer to out layer in each layer of acid spheres soil, and effective Zn content decreases. Along with the increase of distance from acids,the Zn content in the form of Ex-Zn,CARB-Zn,OM-Zn.MnO-Zn,CFeOX-Zn all tends to decrease in each layer of soil; considering the size of Zn content with different form in the same soil layer,the order is CFeOX-Zn>Ex-Zn>AFeo-Zn> OM-Zn>MnO-Zn>CARB-Zn.7.The indoor and field experiment are conducted using different proportional spheres made of concentrated sulphuric acid carbonized corn stover and different proportions of clay.The results demonstrate:Indoor test plant height,width strain and dry weight,and root volume, root weight, root surface area,root length are increased with the increasing spheres volumn and proportion of concentrated sulfuric acid, the Zn content of the plants and roots Zn also shows an increasing trend. Zn content amount of plants in different treatments in different growth stages and corn have an increasing,and dry matter and Zn accumulation at various periods increase.Applying carbonized corn stover and clay processing with a ration of5:10-2g of acid spheres is the most beneficial to increase the yield.