基于ORYZA_V3模型的海涂水稻生物炭施肥优化措施研究

Optimizing Biochar and Fertilizer Application to Improve Rice Production in Reclaimed Coastal Saline Soils Using the ORYZA_V3 Crop Model

【目的】探索施肥管理对沿海垦区盐渍化土壤水稻产量影响。【方法】利用测桶试验数据对ORYZA_V3作物生长模型进行率定与验证,利用验证后的模型定量评估了7个不同施氮肥情景模拟对水稻产量的影响。【结果】ORYZA_V3模型具备模拟不同施肥管理措施下盐渍土水稻生长情况与产量的能力。在低施氮量情景模拟下,施用生物炭对水稻产量影响明显,而高施氮量情景模拟下(施氮量超过235 kg/hm^(2)),土壤中养分达到饱和,施用生物炭对产量影响不明显。添加2%生物炭和5%生物炭处理产量分别在235、141 kg/hm^(2)施氮量情景模拟水平上达到8680.1、8834.1 kg/hm^(2),在此基础上持续添加氮肥对产量影响不明显。【结论】低施氮量情景模拟下,添加5%生物炭对水稻产量促进作用最大,高施氮量情景模拟下,2%生物炭和氮肥联合施用成本相对低,且产量高。

【Background and objective】Fertilization and soil amendments are common agronomic technologies to improve soil properties and safeguard crop production,but how to optimize their applications to save fertilizers without compromising crop yield is an issue that remains largely elusive.The objective of this paper is to fill this knowledge gap.【Method】We took rice grown in the reclaimed coastal saline soils as an example,and simulated its growth in response to biochar and nitrogen fertilization using the ORYZA_V3 crop model.Lysimeter experiments were conducted and the experimental results were used to calibrate the model.The calibrated model was then used to evaluate the impact of different nitrogen fertilizations and biochar amendments on crop growth and yield.【Result】The ORYZA_V3 model was capable of simulating the growth and yield of rice grown in the saline soils.When nitrogen application was low,amending the soil with biochar can increase the rice yield at significant level.However,the improvement depends on nitrogen application rate.When nitrogen application was more than 235 kg/hm^(2),nitrogen did not appear to be a limiting factor for the crop and the efficacy of amending the soil with biochar for improving crop growth and yield was also waning.For example,when the nitrogen fertilization was 235 kg/hm^(2),adding 2%of biochar(w/w)gave a yield 8680.1 kg/hm^(2),while when the nitrogen fertilization was 141 kg/hm^(2),add 5%of biochar could increase the rice yield to 8834.1 kg/hm^(2).Amending the saline soil with biochar is hence an effective way to reduce nitrogen application without compromising crop yield.【Conclusion】The efficacy of amending the reclaimed coastal saline soils with biochar to improve rice yield was when nitrogen fertilization application was low,and its efficacy waned as the nitrogen application increased.These results have important implications for rice production in regions with salt-affected soils.