江西是中国双季稻的主要种植地区。气候变化严重影响了双季稻生产。基于江西省1981—2022年逐日气象资料和双季稻作物资料,对DSSAT模型进行调参验证;利用验证后的DSSAT模型,分析江西省双季稻生长期和产量空间分布和时间变化趋势;采用t...江西是中国双季稻的主要种植地区。气候变化严重影响了双季稻生产。基于江西省1981—2022年逐日气象资料和双季稻作物资料,对DSSAT模型进行调参验证;利用验证后的DSSAT模型,分析江西省双季稻生长期和产量空间分布和时间变化趋势;采用t检验方法,明确气候变化对江西早稻和晚稻的影响差异。结果表明:(1)江西早稻(晚稻)播种期至开花期天数、播种期至成熟期天数和产量模拟值与观测值的归一化均方根误差分别为1.87%(1.86%)、2.05%(2.36%)和6.05%(7.30%),D指标分别为0.97(0.98)、0.96(0.96)和0.95(0.94);(2)固定播期和品种条件下,1981—2022年江西早稻和晚稻生长期均呈显著缩短趋势,平均每10年分别减少2.22 d和1.61 d;研究期间江西早稻和晚稻潜在产量均呈显著下降趋势,平均每10年分别减少181.30 kg hm^(-2)和276.16 kg hm^(-2);(3)t检验表明,江西早稻生长期气候倾向率极显著地小于晚稻,而江西早稻潜在产量气候倾向率极显著地大于晚稻。DSSAT模型可较好的模拟江西双季稻生长发育和产量。气候变化对江西早稻生长期和晚稻潜在产量影响更加明显。本研究为江西双季稻作物模型研究、产量预报和气候变化评估提供了科学依据。展开更多
Information is limited on the potential of double-cropping cowpea (Vigna unguiculata L.) and wheat (Triticum aestivum L.) in the semiarid region of the southern United States. Using the Decision Support System for Agr...Information is limited on the potential of double-cropping cowpea (Vigna unguiculata L.) and wheat (Triticum aestivum L.) in the semiarid region of the southern United States. Using the Decision Support System for Agrotechnology Transfer (DSSAT) crop model and weather data of 80 years, we assessed the possibility of cowpea-wheat double-cropping in this region for grain purpose as affected by planting date and N application rate. Results showed that the possibility of double-cropping varied from 0% to 65%, depending on the cropping system. The possibility was less with systems comprising earlier planting dates of wheat and later planting dates of cowpea. Results indicated that cowpea-wheat double-cropping could be beneficial only when no N was applied, with wheat planted on October 15 or later. At zero N, the double-crops of cowpea planted on July 15 and wheat planted on November 30 were the most beneficial of all the 72 double-cropping systems studied. With a delay in planting cowpea, the percentage of beneficial double-cropping systems decreased. At N rates other than zero, fallow-wheat monocropping systems were more beneficial than cowpea-wheat double-cropping systems, and the benefit was greater at a higher N rate. At 100 kg N ha<sup>-1</sup>, the monocrop of wheat planted on October 15 was the most beneficial of all the 94 systems studied. Results further showed that fallow-wheat yields increased almost linearly with an increase in N rate from 0 to 100 kg∙ha<sup>-1</sup>. Fallow-wheat grain yields were quadratically associated with planting dates. With an increase in N rate, wheat yields reached the peak with an earlier planting date. Wheat yields produced under monocropping systems were greater than those produced under double-cropping systems for any cowpea planting date. Cowpea yields produced under monocropping systems were greater than those produced under any double-cropping system. The relationship between cowpea grain yields and planting dates was quadratic, with July 1 planting date associated with the maximum yields.展开更多
作物模型为人们认识旱区农业生境过程并对其进行调控提供了一种有效的工具。为了探讨小麦生长模拟模型DSSAT-CERES-Wheat能否准确模拟水分胁迫条件下旱区冬小麦的生长发育和产量形成过程,同时确定参数估计和模型验证的最优方案,该研究...作物模型为人们认识旱区农业生境过程并对其进行调控提供了一种有效的工具。为了探讨小麦生长模拟模型DSSAT-CERES-Wheat能否准确模拟水分胁迫条件下旱区冬小麦的生长发育和产量形成过程,同时确定参数估计和模型验证的最优方案,该研究进行了连续两季（2012.10-2013.06和2013.10-2014.06）的冬小麦分段受旱田间试验。试验将冬小麦整个生育期划分为越冬、返青、拔节、抽穗和灌浆5个主要生长阶段,每相邻两个生长阶段连续受旱,形成4个不同的受旱时段水平（D1-D4）,根据小麦生育期的需水量,设置灌水定额分别为40和80 mm 2个水平（I1和I2）,共形成8个处理,每处理3次重复,在遮雨棚内采用裂区试验布置,此外在旁边设置1个各生育期全灌水的对照处理。文中设置了5套不同的参数估计和验证方案,利用DSSAT-GLUE参数估计模块得到不同的参数估计结果。通过对比分析冬小麦物候期、单粒质量、生物量、产量、以及土壤水分含量的模拟值和实测值之间的差异,以确定利用DSSAT-CERES-Wheat模型模拟旱区冬小麦生境过程的精度。结果表明,参数P1V（最适温度条件下通过春化阶段所需天数）和G3（成熟期非水分胁迫下单株茎穂标准干质量）具有较强的变异性,变异系数分别为19.07%和16.34%,受基因型-环境互作的影响较大,而其他参数的变异性则较弱,变异系数均小于10%;DSSAT-GLUE参数估计工具具有较好的收敛性,不同参数估计方案所得的参数值具有一定的一致性;不同的参数估计方案所得的模型输出结果有较大差异,其中参数估计方案1（利用两季试验中的充分灌溉处理CK数据进行参数估计,其他不同阶段受旱处理数据进行验证）的模型校正和验证精度最高,其中模型校正的绝对相对误差（absolute relative error,ARE）和相对均方根误差（relative root mean squared error,RRMSE）分别为4.89%和5.18%。在冬小麦抽穗期和灌浆期受旱时,DSSAT-CERES-Wheat模型可以较好地模拟小麦的生长发育过程以及土壤水分的动态变化,但是在越冬期和返青期受旱时,模拟结果相对较差,并且随着受旱时段提前和受旱程度的加重,模拟精度将变得更低。此外,该模型无法模拟由不同水分胁迫造成的冬小麦物候期差异,需要对模型进行相应的改进。交叉验证表明DSSAT-CERES-Wheat模型模拟该研究中不同水分胁迫条件下冬小麦生长和产量的总体性误差在15%~18%左右。总之,DSSAT-CERES-Wheat模型在模拟旱区冬小麦生境过程时存在着一定的局限性,若要更广泛地将该模型应用在中国干旱半干旱地区的冬小麦生产管理和研究,有必要对冬小麦营养生长阶段前期的水分胁迫响应机制和模拟方法进行进一步的深入研究。展开更多
文摘江西是中国双季稻的主要种植地区。气候变化严重影响了双季稻生产。基于江西省1981—2022年逐日气象资料和双季稻作物资料,对DSSAT模型进行调参验证;利用验证后的DSSAT模型,分析江西省双季稻生长期和产量空间分布和时间变化趋势;采用t检验方法,明确气候变化对江西早稻和晚稻的影响差异。结果表明:(1)江西早稻(晚稻)播种期至开花期天数、播种期至成熟期天数和产量模拟值与观测值的归一化均方根误差分别为1.87%(1.86%)、2.05%(2.36%)和6.05%(7.30%),D指标分别为0.97(0.98)、0.96(0.96)和0.95(0.94);(2)固定播期和品种条件下,1981—2022年江西早稻和晚稻生长期均呈显著缩短趋势,平均每10年分别减少2.22 d和1.61 d;研究期间江西早稻和晚稻潜在产量均呈显著下降趋势,平均每10年分别减少181.30 kg hm^(-2)和276.16 kg hm^(-2);(3)t检验表明,江西早稻生长期气候倾向率极显著地小于晚稻,而江西早稻潜在产量气候倾向率极显著地大于晚稻。DSSAT模型可较好的模拟江西双季稻生长发育和产量。气候变化对江西早稻生长期和晚稻潜在产量影响更加明显。本研究为江西双季稻作物模型研究、产量预报和气候变化评估提供了科学依据。
文摘Information is limited on the potential of double-cropping cowpea (Vigna unguiculata L.) and wheat (Triticum aestivum L.) in the semiarid region of the southern United States. Using the Decision Support System for Agrotechnology Transfer (DSSAT) crop model and weather data of 80 years, we assessed the possibility of cowpea-wheat double-cropping in this region for grain purpose as affected by planting date and N application rate. Results showed that the possibility of double-cropping varied from 0% to 65%, depending on the cropping system. The possibility was less with systems comprising earlier planting dates of wheat and later planting dates of cowpea. Results indicated that cowpea-wheat double-cropping could be beneficial only when no N was applied, with wheat planted on October 15 or later. At zero N, the double-crops of cowpea planted on July 15 and wheat planted on November 30 were the most beneficial of all the 72 double-cropping systems studied. With a delay in planting cowpea, the percentage of beneficial double-cropping systems decreased. At N rates other than zero, fallow-wheat monocropping systems were more beneficial than cowpea-wheat double-cropping systems, and the benefit was greater at a higher N rate. At 100 kg N ha<sup>-1</sup>, the monocrop of wheat planted on October 15 was the most beneficial of all the 94 systems studied. Results further showed that fallow-wheat yields increased almost linearly with an increase in N rate from 0 to 100 kg∙ha<sup>-1</sup>. Fallow-wheat grain yields were quadratically associated with planting dates. With an increase in N rate, wheat yields reached the peak with an earlier planting date. Wheat yields produced under monocropping systems were greater than those produced under double-cropping systems for any cowpea planting date. Cowpea yields produced under monocropping systems were greater than those produced under any double-cropping system. The relationship between cowpea grain yields and planting dates was quadratic, with July 1 planting date associated with the maximum yields.
文摘作物模型为人们认识旱区农业生境过程并对其进行调控提供了一种有效的工具。为了探讨小麦生长模拟模型DSSAT-CERES-Wheat能否准确模拟水分胁迫条件下旱区冬小麦的生长发育和产量形成过程,同时确定参数估计和模型验证的最优方案,该研究进行了连续两季（2012.10-2013.06和2013.10-2014.06）的冬小麦分段受旱田间试验。试验将冬小麦整个生育期划分为越冬、返青、拔节、抽穗和灌浆5个主要生长阶段,每相邻两个生长阶段连续受旱,形成4个不同的受旱时段水平（D1-D4）,根据小麦生育期的需水量,设置灌水定额分别为40和80 mm 2个水平（I1和I2）,共形成8个处理,每处理3次重复,在遮雨棚内采用裂区试验布置,此外在旁边设置1个各生育期全灌水的对照处理。文中设置了5套不同的参数估计和验证方案,利用DSSAT-GLUE参数估计模块得到不同的参数估计结果。通过对比分析冬小麦物候期、单粒质量、生物量、产量、以及土壤水分含量的模拟值和实测值之间的差异,以确定利用DSSAT-CERES-Wheat模型模拟旱区冬小麦生境过程的精度。结果表明,参数P1V（最适温度条件下通过春化阶段所需天数）和G3（成熟期非水分胁迫下单株茎穂标准干质量）具有较强的变异性,变异系数分别为19.07%和16.34%,受基因型-环境互作的影响较大,而其他参数的变异性则较弱,变异系数均小于10%;DSSAT-GLUE参数估计工具具有较好的收敛性,不同参数估计方案所得的参数值具有一定的一致性;不同的参数估计方案所得的模型输出结果有较大差异,其中参数估计方案1（利用两季试验中的充分灌溉处理CK数据进行参数估计,其他不同阶段受旱处理数据进行验证）的模型校正和验证精度最高,其中模型校正的绝对相对误差（absolute relative error,ARE）和相对均方根误差（relative root mean squared error,RRMSE）分别为4.89%和5.18%。在冬小麦抽穗期和灌浆期受旱时,DSSAT-CERES-Wheat模型可以较好地模拟小麦的生长发育过程以及土壤水分的动态变化,但是在越冬期和返青期受旱时,模拟结果相对较差,并且随着受旱时段提前和受旱程度的加重,模拟精度将变得更低。此外,该模型无法模拟由不同水分胁迫造成的冬小麦物候期差异,需要对模型进行相应的改进。交叉验证表明DSSAT-CERES-Wheat模型模拟该研究中不同水分胁迫条件下冬小麦生长和产量的总体性误差在15%~18%左右。总之,DSSAT-CERES-Wheat模型在模拟旱区冬小麦生境过程时存在着一定的局限性,若要更广泛地将该模型应用在中国干旱半干旱地区的冬小麦生产管理和研究,有必要对冬小麦营养生长阶段前期的水分胁迫响应机制和模拟方法进行进一步的深入研究。
基金Challenge Program on Water&Food"Conservation Agriculture for the Dryland Areas of the Yellow River Basin"(CN228)"十一五"国家科技支撑计划项目"黄土高原水土流失综合治理工程关键支撑技术研究"(2006BAD09B04)欧盟DESIRE项目(037046)
