Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at diff...Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at different yield levels(medium yielding site(MYS)Luzhou City and high yielding site(HYS)Deyang City had not been described.Field experiments with hybrid rice Rongyou1015 were conducted to study the effects of two plant densities.High plant density(HD),low plant density(LD)and four N rates(without N,N_(0);a recommended N rate of 195 kg•hm^(-2),N_(CK);a 23%reduction in N rate,N_(-23%);a 46%reduction in N rate,N_(-46%)on yield attributes,grain yield,TNU and NUE of hybrid rice were studied under different yield levels in 2016-2017.The results showed that the grain yield and NUE of hybrid rice in response to plant density and N rate varied with yield levels.For MYS,reducing N rate by 46%result in significantly lower grain yield at LD treatment;whereas at HD treatment the grain yield of hybrid rice under N_(-46%) and N_(CK) were equal.For HYS,reducing N rate by 46% result in significantly lower grain yield regardless of low plant density and high plant density;however,a reduction in N rate by 23%increased grain yield,AE_(N) by 36%,PFP_(N) by 31% and RE_(N) by 11% over N_(CK) at HD treatment.Higher grain yield of hybrid rice under the combination of HD with low N rate was attributable to improvement in spikelets per panicle and harvest index.The results suggested that high plant density with low N rate might be an effective approach to improve grain yield and NUE in rice production,but reduction in N application rate was determined,according to yield levels.展开更多
为明确秸秆还田和施磷量对旱地小麦籽粒淀粉品质和相关酶合成的影响,以洛旱22为材料,采用裂区试验,主区为玉米秸秆还田处理,分别为秸秆不还田(S0)、秸秆全量还田(S1),副区为施磷量,设5个水平分别为0 kg hm^(-2)(P0)、75.0 kg hm^(-2)(P1...为明确秸秆还田和施磷量对旱地小麦籽粒淀粉品质和相关酶合成的影响,以洛旱22为材料,采用裂区试验,主区为玉米秸秆还田处理,分别为秸秆不还田(S0)、秸秆全量还田(S1),副区为施磷量,设5个水平分别为0 kg hm^(-2)(P0)、75.0 kg hm^(-2)(P1)、112.5 kg hm^(-2)(P2)、150.0 kg hm^(-2)(P3)、187.5 kg hm^(-2)(P4),研究了秸秆还田和施磷量对小麦籽粒产量、淀粉及其相关酶活性的影响。结果表明,秸秆还田和增施磷肥均能提高小麦穗数、穗粒数、千粒重和产量,相同秸秆还田处理下均随施磷量的提高呈先升后降趋势,且除千粒重外均表现为P3最高。2个年度,小麦产量在S1P3处理下较S1P0分别提高了35.70%与49.32%;小麦籽粒直链淀粉、支链淀粉、总淀粉的含量随生育时期推进均呈持续升高趋势,随施磷量的提高均呈先升后降趋势,总体上在P3水平达到最大。在同一施磷水平下,小麦籽粒直链淀粉、支链淀粉含量均表现为S1大于S0处理。2021—2022年度秸秆还田和施磷的互作效应对支/直淀粉比例在花后5~20 d有显著或极显著的影响;2022—2023年二者的互作仅对花后5 d支/直淀粉比例有显著影响。2年度,随生育时期的推进,各处理籽粒蔗糖合成酶、腺苷二磷酸葡萄糖焦磷酸化酶、可溶性淀粉合成酶、束缚性淀粉合成酶活性均表现为先增后降趋势,而籽粒磷酸蔗糖合成酶呈持续降低趋势。无论秸秆还田与否,腺苷二磷酸葡萄糖焦磷酸化酶与束缚性淀粉合成酶活性均随施磷水平的升高表现为先增后降趋势,总体在P3处理最高。综上,秸秆还田配施磷150 kg hm^(-2)(S1P3)是本试验条件下小麦最适种植方式。展开更多
基金Supported by Earmarked Fund for Modern Agro-industry Technology of China(CARS-01-25)National Key Research and Development Program of China(2017YFD0301705)Foundation of Youth Science Program of Sichuan Agricultural Sciences Academy(2019QNJJ-020)。
文摘Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at different yield levels(medium yielding site(MYS)Luzhou City and high yielding site(HYS)Deyang City had not been described.Field experiments with hybrid rice Rongyou1015 were conducted to study the effects of two plant densities.High plant density(HD),low plant density(LD)and four N rates(without N,N_(0);a recommended N rate of 195 kg•hm^(-2),N_(CK);a 23%reduction in N rate,N_(-23%);a 46%reduction in N rate,N_(-46%)on yield attributes,grain yield,TNU and NUE of hybrid rice were studied under different yield levels in 2016-2017.The results showed that the grain yield and NUE of hybrid rice in response to plant density and N rate varied with yield levels.For MYS,reducing N rate by 46%result in significantly lower grain yield at LD treatment;whereas at HD treatment the grain yield of hybrid rice under N_(-46%) and N_(CK) were equal.For HYS,reducing N rate by 46% result in significantly lower grain yield regardless of low plant density and high plant density;however,a reduction in N rate by 23%increased grain yield,AE_(N) by 36%,PFP_(N) by 31% and RE_(N) by 11% over N_(CK) at HD treatment.Higher grain yield of hybrid rice under the combination of HD with low N rate was attributable to improvement in spikelets per panicle and harvest index.The results suggested that high plant density with low N rate might be an effective approach to improve grain yield and NUE in rice production,but reduction in N application rate was determined,according to yield levels.
文摘为明确秸秆还田和施磷量对旱地小麦籽粒淀粉品质和相关酶合成的影响,以洛旱22为材料,采用裂区试验,主区为玉米秸秆还田处理,分别为秸秆不还田(S0)、秸秆全量还田(S1),副区为施磷量,设5个水平分别为0 kg hm^(-2)(P0)、75.0 kg hm^(-2)(P1)、112.5 kg hm^(-2)(P2)、150.0 kg hm^(-2)(P3)、187.5 kg hm^(-2)(P4),研究了秸秆还田和施磷量对小麦籽粒产量、淀粉及其相关酶活性的影响。结果表明,秸秆还田和增施磷肥均能提高小麦穗数、穗粒数、千粒重和产量,相同秸秆还田处理下均随施磷量的提高呈先升后降趋势,且除千粒重外均表现为P3最高。2个年度,小麦产量在S1P3处理下较S1P0分别提高了35.70%与49.32%;小麦籽粒直链淀粉、支链淀粉、总淀粉的含量随生育时期推进均呈持续升高趋势,随施磷量的提高均呈先升后降趋势,总体上在P3水平达到最大。在同一施磷水平下,小麦籽粒直链淀粉、支链淀粉含量均表现为S1大于S0处理。2021—2022年度秸秆还田和施磷的互作效应对支/直淀粉比例在花后5~20 d有显著或极显著的影响;2022—2023年二者的互作仅对花后5 d支/直淀粉比例有显著影响。2年度,随生育时期的推进,各处理籽粒蔗糖合成酶、腺苷二磷酸葡萄糖焦磷酸化酶、可溶性淀粉合成酶、束缚性淀粉合成酶活性均表现为先增后降趋势,而籽粒磷酸蔗糖合成酶呈持续降低趋势。无论秸秆还田与否,腺苷二磷酸葡萄糖焦磷酸化酶与束缚性淀粉合成酶活性均随施磷水平的升高表现为先增后降趋势,总体在P3处理最高。综上,秸秆还田配施磷150 kg hm^(-2)(S1P3)是本试验条件下小麦最适种植方式。
