Efficient nitrogen management is crucial for developing sustainable strategies aimed at enhancing yield while mitigating negative environmental impacts.However,research focusing on this aspect in the production of fre...Efficient nitrogen management is crucial for developing sustainable strategies aimed at enhancing yield while mitigating negative environmental impacts.However,research focusing on this aspect in the production of fresh maize is limited.Therefore,this study analyzed the effects of nitrogen application rates on the yields of 40 sweet and 44 waxy maize varieties at five sites in Zhejiang Province,China,from 2015 to 2019.The nitrogen application rates were categorized as either relatively high(RHN,>300 kg ha^(-1) for sweet maize and>320 kg ha^(-1) for waxy maize)or relatively low(RLN).An increase in nitrogen application rates significantly reduced nitrogen fertilizer partial productivity in both sweet and waxy maize(R^(2)=0.616,P<0.01;R^(2)=0.643,P<0.01),indicating that the optimum nitrogen application rates in this study might be the lowest values(160 kg ha^(-1) for sweet maize and 180 kg ha^(-1) for waxy maize).The kernel number per ear of sweet maize had a potentially more significant impact on fresh grain yield than the 1,000-fresh kernel weight under both RLN and RHN.In waxy maize,1,000-kernel weight contributed more to fresh grain yield under RLN,while kernel number per ear and 1,000-kernel weight cooperatively affected the yield under RHN.This study found that sweet maize required taller plant and ear heights,along with an optimal ear-plant height ratio,to enhance dry matter accumulation and increase source size,particularly under RLN,and to ultimately achieve a higher fresh grain yield.In contrast,a lower ear height and ear-plant height ratio in waxy maize probably contributed more to the greater kernel number and weight under RLN,likely due to a lower ear height which can reduce the distance between sink and source,enabling more efficient photoassimilate allocation to the ear.展开更多
This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice.Breeding nitrogen efficient cultivars without sacrificing rice yield potential,improving grain fill in later...This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice.Breeding nitrogen efficient cultivars without sacrificing rice yield potential,improving grain fill in laterflowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency.Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars.Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets.Several practices,such as post-anthesis controlled soil drying,an alternate wetting and moderate soil drying regime during the whole growing season,and non-flooded straw mulching cultivation,could substantially increase grain yield and water use efficiency,mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index.Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.展开更多
基金funded by the Zhejiang Science and Technology Major Program on Agricultural New Variety Breeding,China(2021C02064-4)the Zhejiang Province“Three Rural and Nine Party”Science and Technology Cooperation Plan Project,China(2023SNJF002).
文摘Efficient nitrogen management is crucial for developing sustainable strategies aimed at enhancing yield while mitigating negative environmental impacts.However,research focusing on this aspect in the production of fresh maize is limited.Therefore,this study analyzed the effects of nitrogen application rates on the yields of 40 sweet and 44 waxy maize varieties at five sites in Zhejiang Province,China,from 2015 to 2019.The nitrogen application rates were categorized as either relatively high(RHN,>300 kg ha^(-1) for sweet maize and>320 kg ha^(-1) for waxy maize)or relatively low(RLN).An increase in nitrogen application rates significantly reduced nitrogen fertilizer partial productivity in both sweet and waxy maize(R^(2)=0.616,P<0.01;R^(2)=0.643,P<0.01),indicating that the optimum nitrogen application rates in this study might be the lowest values(160 kg ha^(-1) for sweet maize and 180 kg ha^(-1) for waxy maize).The kernel number per ear of sweet maize had a potentially more significant impact on fresh grain yield than the 1,000-fresh kernel weight under both RLN and RHN.In waxy maize,1,000-kernel weight contributed more to fresh grain yield under RLN,while kernel number per ear and 1,000-kernel weight cooperatively affected the yield under RHN.This study found that sweet maize required taller plant and ear heights,along with an optimal ear-plant height ratio,to enhance dry matter accumulation and increase source size,particularly under RLN,and to ultimately achieve a higher fresh grain yield.In contrast,a lower ear height and ear-plant height ratio in waxy maize probably contributed more to the greater kernel number and weight under RLN,likely due to a lower ear height which can reduce the distance between sink and source,enabling more efficient photoassimilate allocation to the ear.
基金The National Natural Science Foundation of China(3146114301531271641,31471438,91317307)+1 种基金the National Key Technology Support Program of China(2011BAD16B14,2012BAD04B08,2014AA10A605)the Priority Academic Program Development of Jiangsu Higher Education Institutions,Jiangsu Creation Program for Post-graduation Students(KYZZ_0364)are thanked for their financial support.
文摘This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice.Breeding nitrogen efficient cultivars without sacrificing rice yield potential,improving grain fill in laterflowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency.Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars.Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets.Several practices,such as post-anthesis controlled soil drying,an alternate wetting and moderate soil drying regime during the whole growing season,and non-flooded straw mulching cultivation,could substantially increase grain yield and water use efficiency,mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index.Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.
