摘要
对青海高原农田特有春小麦(Triticum aestivum)+豆科绿肥栽培模式,为揭示绿肥还田对于春小麦产量和土壤有机碳(SOC)的长期效应,本研究采用小区试验与模型相结合的方法探索适宜青海高原的绿肥还田方式。本研究采用裂区试验设计,主区为秋闲期复种绿肥翻压还田(G)和不种绿肥不还田(CK),副区为后茬春小麦化肥用量,设置100%常规施肥(F_(100),225 kg·hm^(-2)N、112.5 kg·hm^(-2)P_(2)O_(5))、70%常规施肥(F_(70),157.5 kg·hm^(-2)N、78.75 kg·hm^(-2)P_(2)O_(5))和不施化肥(F_(0)),共6个处理,基于2019-2022年的田间试验数据对反硝化-分解(DNDC)模型进行率定与验证,用验证过的模型对不同处理下土壤有机碳和小麦产量的长期变化规律进行模拟研究。结果表明:DNDC模型可以较好地模拟土壤有机碳和小麦产量,率定和验证过程中土壤有机碳模拟值和实测值的NRMSE值介于0.017-0.295,R^(2)介于0.763-0.924,小麦产量模拟值和实测值的NRSME值范围为0.160-0.280,R^(2)均大于0.75,表明模拟值和实测值具有一致性,可以用校准验证过的模型模拟0-50 cm土层土壤SOC和小麦产量;未来30年的模拟结果显示,绿肥翻压还田可以增加土壤SOC,具体表现为F_(70)+G>F_(100)+G>F_(0)+G>F_(100)> F_(70)> F_(0);0-50 cm土层土壤SOC储量30年变化依次为172.82、136.91、65.21、-35.61、-46.70和-143.95kg·hm^(-2),产量趋势为F_(70)+G>F_(100)+>G>F_(100)>F_(70)>F_(0)+G>F_(0),绿肥翻压还田配施化肥增产效果较好,F_(0)+G、F_(70)+G和F_(100)+G比无绿肥处理(F_(0)、F_(70)、F_(100))下小麦产量分别提高了85.7%、87.5%和20.0%;模拟的土壤有机碳含量和小麦产量具有一定的相关性。综合来看,长期复种绿肥翻压还田配施70%的化肥的固碳增产效果最佳。
In response to the unique spring wheat leguminous green manure cultivation model employed in the farmland of the Qinghai Plateau,this study investigates the long-term effects of green manure return on spring wheat yield and soil organic carbon(SOC).A combination of plot experiments and models was used to explore a suitable green manure return method for Qinghai Plateau.A split plot experimental design was adopted,with the main plot being the autumn fallow period,when multiple green manures are used for turning over and returning to the field(G)and no green manure is used for returning to the field(CK).The sub plot is the amount of fertilizer used for subsequent spring wheat,with 100%conventional fertilization(F_(100),225 kg·ha^(-1) N and 112.5 kg·ha^(-1) P_(2)O_(5)),70%conventional fertilization(F_(70),157.5 kg·ha^(-1) N and 78.75 kg·ha^(-1) P_(2)O_(5)),and no fertilizer application(F_(0)).A total of six treatments were used to calibrate and validate the denitrification decomposition(DNDC)model based on field experimental data from 2019 to 2022.The validated model was used to simulate the long-term changes in SOC and wheat yield under different treatments.The results showed that the DNDC model effectively simulated SOC and wheat yield.The NRMSE values of simulated and measured SOC during the calibration and validation process ranged from 0.017 to 0.295,with R^(2) values between 0.763 and 0.924.The NRSME values of simulated and measured wheat yields ranged from 0.160 to 0.280,with R^(2)>0.75 for both,indicating consistency between the simulated and measured values.A calibrated and validated model can be used to simulate soil SOC and wheat yield in 0-50 cm soil.The simulation results for 30 years showed that returning green manure to the field increased soil SOC,specifically manifested as F_(70)+G>F_(100)+G>F_(0)+G>F_(100)>F_(70)>F_(0).The 30-year variation of soil SOC storage in the 0-50 cm soil layer was 172.82 kg·ha^(-1),as follows:136.91,65.21,‒35.61,‒46.70,and‒143.95 kg·ha^(-1).By contrast,the yield appeared to follow a trend of F_(70)+G>F_(100)+G>F_(100)>F_(70)>F_(0)+G>F_(0).The combination of green manure and returning to the field with chemical fertilizer showed a better yield increase effect.Compared with treatment without green manure,the wheat yield under F_(0)+G,F_(70)+G,and F_(100)+G treatment increased by 85.7%,87.5%,and 20.0%,respectively.The simulated SOC content showed a correlation with wheat yield.Overall,long-term multiple cropping of green manure with 70%chemical fertilizer was found to have the best effect on carbon sequestration and yield increase.
作者
肖玉涛
李正鹏
宋明丹
段豆豆
韩梅
XIAO Yutao;LI Zhengpeng;SONG Mingdan;DUAN Doudou;HAN Mei(Academy of Agriculture and Forestry Sciences,Qinghai University,Xining 810016,Qinghai,China)
出处
《草业科学》
CAS
CSCD
北大核心
2024年第2期332-344,共13页
Pratacultural Science
基金
青海省基础研究计划项目(2022-ZJ-741)
财政部和农业农村部:国家现代农业产业技术体系资助项目(CARS-22)。
关键词
毛叶苕子
绿肥还田
春小麦
模型评价
模拟预测
施氮量
有机碳
Vicia villosa
green manure
spring wheat
model evaluation
simulated prediction
nitrogen application rate
organic carbon
