| In order to find out the best level of zinc application for the growth of maize in saline-alkali soil in north area of Yinchuan,Ningxia,the field random block test was conducted with Kehe 699 as experimental material,six treatments were set up:T0:0kg·hm-2;T1:7.5kg·hm-2;T2:15kg·hm-2;T3:22.5kg·hm-2;T4:30kg·hm-2;T5:37.5kg·hm-2.The effects of different zinc fertilizer application on the growth,photosynthetic characteristics,physiological characteristics,nutrient absorption and transportation,yield and quality of maize was studied systematically.The main results are as follows:(1)The height,stem diameter,leaf area and dry matter accumulation of maize in the treatment of zinc were better than the treatment without zinc fertilizer application in the growth period,and the best treatment was T3.The height,stem diameter and leaf area of T3 were 16.5%,26.9%and 8.3%higher than T0 at the tasseling stage.The dry matter accumulation of T3 was 65.6%higher than T0,but excessive zinc application was not beneficial to the accumulation of dry matter,and even made the dry matter weight decrease.(2)Appropriate amount of zinc fertilizer application was significantly improved maize photosynthesis.The net photosynthetic rate,intercellular carbon dioxide,stomatal conductance and transpiration rate of maize all reached the maximum value at 22.5kg·hm-2(T3)in each period.The net photosynthetic rate of maize was 33.6%,14.0%,9.7%,10.0%and 10.3%higher than that of T0,T1,T2,T4 and T5 at tasseling stage.Reasonable application of zinc fertilizer could also increase the contents of chlorophyll a,chlorophyll B,chlorophyll Carotenoid and chlorophyll a+b in maize leaves,and then enhance the ability of absorption and transformation of light energy,keep high photosynthetic capacity of maize.(3)Fv/F0?Fv/Fm?PI were highest when zinc application was 22.5kg·hm-2,and the lowest was T0,which indicated that reasonable zinc application could enhance the photochemical efficiency of PSII and the photosynthetic capacity of maize.(4)The content of proline,MDA and relative conductivity shows the treatment with zinc ferifilizer was lower than no zinc treatment observably.The activities of SOD,CAT and POD were increased than that treatment without zinc fertilizer.The results showed that proper application of zinc fertilizer could reduce the damage of cell structure,improve the resistance of maize and delay the senescence of plants.(5)Zinc fertilizer promoted the accumulation of nutrients in maize.The accumulation of zinc,nitrogen,phosphorus and potassium of T3 were 125.8%,55.0%,45.8%and 50.9%higher under the treatment no zinc fertilizers.Meanwhile,the transfer and distribution of Zn,N,P and K from the vegetative organs to the grains were also increased,thus increasing the accumulation of nutrients in the grains.Zinc transfer rate and contribution rate were the best when zinc application was 22.5kg·hm-2,and transfer rate and contribution rate decreased when zinc was not applied or above the level.(6)Appropriate application of zinc fertilizer could significantly improve the ear characters,increase the yield and quality of maize.The ear length and ear diameter of maize in T3 treatment were the largest,which increased by 9.2%and 3.4%than T0.The length of bare tip in T3 was decreased by 43.9%than T0.The number of rows per ear and the number of grains per row increased first and then decreased with the increase of zinc application.The yield increase rates were 11.3%,18.6%,24.0%,11.9%and 3.2%,respectively,indicating that the zinc application of 22.5kg·hm-2 was more conducive to the growth of corn ear,and the yield reached 12433.86kg·hm-2 at this time.The yield regression equation shows that the optimum amount of zinc application was 19.5kg·hm-2.The content of crude protein and soluble sugar in maize grain increased significantly under zinc fertilizer application,but the effect of zinc fertilizer on starch content was not significant... |
PDF Full Text Request