Plant-soil interactions in changing rice cropping systems: Nutrient balances and yield gap analysis

改变水稻种植系统中的植物-土壤相互作用：养分平衡和产量差距分析

• 批准号: 261685412
• 负责人: Professor Dr. Mathias Becker
• 金额: --
• 依托单位: Bereich Pflanzenernährung
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/261685412?language=en
• 关键词: Plant; soil; interactions; changing; rice

While phase I of ICON mainly addressed the risks and trade-offs associated with an aerobic soil phase in rice-based systems on the research site at IRRI, phase II will focus on the opportunities and potential agronomic benefits of these emerging cropping patterns and expand the studies to the major rice-growing environments in Luzon. The integration of an aerobic soil phase offers opportunities for crop diversification, residue management and nutrient cycling. In the predominating rice double cropping system, straw is generally removed and burnt. The application of straw to upland crops, on the other hand, is common practice in many production systems in Asia and elsewhere. Application of rice straw in the post-rice niche allows for the return of substantial amounts of K and Si, the temporary microbial immobilization of soil nitrate, enhancement of soil (micro-)biological activity and improvement of soil physical attributes. In addition, straw mulch can reduce variations in topsoil moisture and thus possibly mitigate crack formation.The yield gaps (differences between the potential or achievable, and farmers¿ actual yields) are relatively large in most rice-growing environments of the Philippines. We hypothesize that these yield gaps can be partially closed through improvements associated with residue return and the integration of upland crops and leguminous cover crops in the niche following wet season rice. The extent of such effects depends on prevailing edaphic conditions and farming systems¿ attributes. In four major rice-growing environments of Luzon (incl. the core experiment at IRRI), we shall compare the agronomic performance and quantify partial yield gaps in different cropping and management systems (rice double crop vs. rice ¿ upland crops, with / without straw mulch, with / without ¿nitrate catch crops¿). Actual farmer¿s and simulated (ORYZA2000) potential yields, as well as nutrient balances and agronomic attributes of both rice and the dry season crops will be determined in farmer¿s-managed field plots and in researcher-managed subplots (dry season crop and residue management) at each site. Yield data will be subjected to frontier and to partial yield gap analyses. Seasonal soil N dynamics during the dry-to-wet and the wet-to-dry transition seasons will be determined under different management scenarios, and partial nutrient balances will be established. Selected treatment combinations will subsequently be evaluated regarding their effects on soil biota (SPs 1, 2, and 3), soil physical attributes, incl. crack formation (SP 4), trace gas emissions (SP 5 and 7) and water budgets (SPs 6 and 7). Possible extrapolation domains for relevant options and their impact on closing the yield gap will be specified.

ICON的第一阶段主要解决了与IRRI研究地点的水稻系统中有氧土壤阶段相关的风险和权衡，第二阶段将侧重于这些新兴种植模式的机会和潜在的农艺效益，并将研究扩展到吕宋岛的主要水稻种植环境。有氧土壤阶段的整合为作物多样化、残留物管理和养分循环提供了机会。在占主导地位的水稻两熟制中，秸秆通常被清除并焚烧。另一方面，在亚洲和其他地方的许多生产系统中，将秸秆用于高地作物是常见的做法。稻后生态位施用稻草可归还大量的钾和硅，暂时固定土壤硝态氮，增强土壤（微）生物活性，改善土壤物理性质。此外，秸秆覆盖可以减少表层土壤水分的变化，从而可能减轻裂缝的形成。产量差距（潜在或可实现的产量与农民的实际产量之间的差异）在菲律宾的大多数水稻种植环境中相对较大。我们假设，这些产量差距可以部分关闭，通过改善与残留物的回报和高地作物和豆科覆盖作物在生态位以下湿季稻的整合。这种影响的程度取决于当时的土壤条件和耕作制度的属性。在吕宋岛的四个主要水稻种植环境（包括。IRRI的核心试验），我们将比较不同种植和管理制度（水稻双季与水稻旱作，有/无秸秆覆盖，有/无硝酸盐捕获作物）的农艺表现并量化部分产量差距。真正的农民在每个地点，将在农民管理的田间小区和研究人员管理的子小区（旱季作物和残留物管理）中确定水稻和旱季作物的潜在产量和模拟（ORYZA 2000）产量，以及养分平衡和农艺属性。收益率数据将进行前沿和部分收益率差距分析。将在不同的管理方案下确定干-湿和湿-干过渡季节的季节性土壤氮动态，并建立部分养分平衡。随后将评估选定的处理组合对土壤生物群（SP1、SP2和SP3）、土壤物理属性（包括土壤含水量）和土壤含水量的影响。裂缝形成（SP 4）、痕量气体排放（SP 5和7）和水收支（SP 6和7）。将指定相关选项的可能外推域及其对缩小收益率差距的影响。