Response Of Yield, And Nitrogen And Sulfur Uptake In Summer Maize To Nitrogen And Sulfur Application

Nitrogen and sulfur are both essential to crop growth, and they play a vital role in thephysiological function, morphological growth and grain build-up in crops. Researches on theeffects of nitrogen and sulfur application on crop growth can provide some vital informationfor optimal agricultural production model design, food security and high use efficiency offertilizers. Maize is one of the most important cereal crops in China, and it plays an importantrole in China’s agricultural production. To assess the effects of nitrogen and sulfur applicationon growth, yield and nitrogen and sulfur uptake in summer maize in Guanzhong area, Shaanxiprovince, China field experiments were conducted with a complete randomized block design（for single N and single S experiments） and a central composite rotatable design with twofactors （for N-S interaction experiments） in2013. The morphological characteristics, leafphotosynthetic pigment content, biomass, grain yield, and nitrogen and sulfur uptake of themaize were determined, and the optimal nitrogen and sulfur application rate in the regionwere made with a second-order polynomial equation. The results showed that:i) Biomass and grain yield of summer maize increased as both nitrogen and sulfurapplication increased. For higher maize grain yield, the optimal nitrogen application rate was171.40²39.54kg·N·hm^-2, and the optimal sulfur application rate was50.71⁷7.41kg·S·hm^-2.ii) Plant height, stem diameter, and chlorophyll content increased as both nitrogen andsulfur input. Maize leaf area and leaf area index increased in both nitrogen and sulfurtreatments.iii) Nitrogen accumulation, nitrogen net absorption amount, and nitrogen uptake rate indifferent growth stages increased as both nitrogen and sulfur application increased. Nitrogentranslocation and contribution from vegetative organs to grain increased in both nitrogen andsulfur treatments. Partial nitrogen productivity and apparent nitrogen recovery decreasedwith increasing nitrogen application rate, while agronomic and physiologic nitrogenefficiency increased with nitrogen. For nitrogen accumulation in summer maize, the optimalnitrogen application rate and the optimal sulfur application rate was177.01²49.05kg·N·hm^-2, and52.89⁷7.96kg·S·hm^-2, respectively. iv) Sulfur accumulation, sulfur net absorption amount, and sulfur uptake rate in differentgrowth stages increased in both nitrogen and sulfur treatements. Sulfur translocation fromleaves and stems to grains increased with nitrogen and sulfur application rate. Leaf sulfurtransfer efficiency and contribution to grains decreased in nitrogen treatments, whileincreased in sulfur treatments. Partial sulfur productivity, apparent sulfur recovery, andagronomic sulfur efficiency decreased with sulfur increasing. For sulfur accumulation insummer maize, the optimal nitrogen application rate and the optimal sulfur application ratewas was145.31¹95.45kg·N·hm^-2, and90.18¹26.67kg·S·hm^-2, respectively.Main conclusion: morphological growth, leaf photosynthetic pigment, dry matteraccumulation, grain yield, and nitrogen and sulfur uptake were all improved by nitrogen andsulfur application. In the research region, to obtain the higher grain yield, and nitrogen andsulfur uptake of summer maize, the optimal nitrogen application rate was recommended as145.31²49.05kg·N·hm^-2, while sulfur as50.71¹26.67kg·S·hm^-2.