针对青海高原及高寒地区小麦生产氮肥施用量高、温室气体排放量大等问题,探究绿肥不同还田方式及小麦季不同施氮量对小麦农田温室气体排放和产量的影响,为该区小麦可持续生产提供理论依据和技术支撑。试验于2023—2024年在青海大学农林...针对青海高原及高寒地区小麦生产氮肥施用量高、温室气体排放量大等问题,探究绿肥不同还田方式及小麦季不同施氮量对小麦农田温室气体排放和产量的影响,为该区小麦可持续生产提供理论依据和技术支撑。试验于2023—2024年在青海大学农林科学院试验站进行,采用裂区试验设计,主区为小麦季3个施氮水平:常规施氮(225kg hm^(–2), N2)、减施氮肥30%(158 kg hm^(–2), N1)和不施氮(0 kg hm^(–2), N0);裂区基于上一年度绿肥设置3种还田方式:地上部移除仅根茬还田(RR)、地上部过腹联合根茬还田(SDRR)、地上部及根茬全量还田(RROS)。结果表明,减氮30%结合绿肥过腹+根茬还田(N1SDRR)处理显著降低温室气体排放:CO_(2)排放总量较减氮30%全量还田(N1RROS)降低4.2%;N_(2)O排放总量、CH4吸收总量较N1RROS降低19.1%、提升15.8%;全球增温潜势(GWP)较N1RROS降低5.0%。N1SDRR处理小麦籽粒产量较N1RROS提高4.1%,温室气体排放强度(GHGI)较N1RROS降低14.6%,实现减排稳产。此外, N1SDRR处理土壤有机质、铵态氮含量较N1RROS提升9.1%、22.8%,土壤硝态氮含量较N1RROS降低10.0%;土壤蔗糖酶、脲酶活性较N1RROS分别提高3.2%、7.8%,但土壤亚硝酸还原酶、硝酸还原酶活性分别降低11.9%、5.7%,表明该模式通过提升土壤有机质、调控铵/硝态氮平衡同步降低温室气体排放并维持生产力。随机森林模型进一步表明,土壤蔗糖酶、籽粒产量及土壤有机质是调控温室气体排放强度的关键因子,优化施氮与绿肥还田方式会对土壤碳、氮含量产生影响,可显著降低单位产量碳排放。因此,氮肥减施30%结合绿肥地上部过腹联合根茬还田可改善土壤理化因子和酶活性,有效降低温室气体排放,稳定小麦籽粒产量,是青海高原及高寒地区小麦农田稳产减排的适宜管理措施。展开更多
Straw incorporation is generally considered an effective agricultural management practice that improves nutrient cycling and maintains soil fertility. To study the interactive effects of straw returning factors on soi...Straw incorporation is generally considered an effective agricultural management practice that improves nutrient cycling and maintains soil fertility. To study the interactive effects of straw returning factors on soil organic carbon and available nutrients, a17-month(May 6, 2016 to October 6, 2017) experiment was conducted on straw incorporation by using response surface methodology under a three-factor(straw length, amount, and burying depth), five-level quadratic orthogonal rotation experimental design. Weight was assigned to each indicator for soil carbon and nutrients and then a comprehensive indicator was established. Then, a second-order polynomial model of the three straw returning factors was established using response surface methodology. Results indicated that17 months after straw incorporation, straw amount and burying depth had significant effects on the comprehensive indicator of soil carbon and nutrients. Straw length and the interactions of straw amount and burying depth showed no significant effects on the comprehensive indicator of soil carbon and nutrients. It was concluded that 17 months after straw incorporation, the highest value of the comprehensive indicator of soil carbon and nutrients was achieved when the straw length, amount, and burying depth were approximately 17–20 cm, 740–840 g m^(-2), and 9–13 cm, respectively, which can be recommended as the most suitable parameters for use in straw returning in the study area.展开更多
文摘针对青海高原及高寒地区小麦生产氮肥施用量高、温室气体排放量大等问题,探究绿肥不同还田方式及小麦季不同施氮量对小麦农田温室气体排放和产量的影响,为该区小麦可持续生产提供理论依据和技术支撑。试验于2023—2024年在青海大学农林科学院试验站进行,采用裂区试验设计,主区为小麦季3个施氮水平:常规施氮(225kg hm^(–2), N2)、减施氮肥30%(158 kg hm^(–2), N1)和不施氮(0 kg hm^(–2), N0);裂区基于上一年度绿肥设置3种还田方式:地上部移除仅根茬还田(RR)、地上部过腹联合根茬还田(SDRR)、地上部及根茬全量还田(RROS)。结果表明,减氮30%结合绿肥过腹+根茬还田(N1SDRR)处理显著降低温室气体排放:CO_(2)排放总量较减氮30%全量还田(N1RROS)降低4.2%;N_(2)O排放总量、CH4吸收总量较N1RROS降低19.1%、提升15.8%;全球增温潜势(GWP)较N1RROS降低5.0%。N1SDRR处理小麦籽粒产量较N1RROS提高4.1%,温室气体排放强度(GHGI)较N1RROS降低14.6%,实现减排稳产。此外, N1SDRR处理土壤有机质、铵态氮含量较N1RROS提升9.1%、22.8%,土壤硝态氮含量较N1RROS降低10.0%;土壤蔗糖酶、脲酶活性较N1RROS分别提高3.2%、7.8%,但土壤亚硝酸还原酶、硝酸还原酶活性分别降低11.9%、5.7%,表明该模式通过提升土壤有机质、调控铵/硝态氮平衡同步降低温室气体排放并维持生产力。随机森林模型进一步表明,土壤蔗糖酶、籽粒产量及土壤有机质是调控温室气体排放强度的关键因子,优化施氮与绿肥还田方式会对土壤碳、氮含量产生影响,可显著降低单位产量碳排放。因此,氮肥减施30%结合绿肥地上部过腹联合根茬还田可改善土壤理化因子和酶活性,有效降低温室气体排放,稳定小麦籽粒产量,是青海高原及高寒地区小麦农田稳产减排的适宜管理措施。
基金supported by the Special Fund for Agro-scientific Research in the Public Interest of China (No. 201503116-04)the Science and Technology Achievements Transformation Fund Project of China (No. 2013GB2B200134)
文摘Straw incorporation is generally considered an effective agricultural management practice that improves nutrient cycling and maintains soil fertility. To study the interactive effects of straw returning factors on soil organic carbon and available nutrients, a17-month(May 6, 2016 to October 6, 2017) experiment was conducted on straw incorporation by using response surface methodology under a three-factor(straw length, amount, and burying depth), five-level quadratic orthogonal rotation experimental design. Weight was assigned to each indicator for soil carbon and nutrients and then a comprehensive indicator was established. Then, a second-order polynomial model of the three straw returning factors was established using response surface methodology. Results indicated that17 months after straw incorporation, straw amount and burying depth had significant effects on the comprehensive indicator of soil carbon and nutrients. Straw length and the interactions of straw amount and burying depth showed no significant effects on the comprehensive indicator of soil carbon and nutrients. It was concluded that 17 months after straw incorporation, the highest value of the comprehensive indicator of soil carbon and nutrients was achieved when the straw length, amount, and burying depth were approximately 17–20 cm, 740–840 g m^(-2), and 9–13 cm, respectively, which can be recommended as the most suitable parameters for use in straw returning in the study area.
