Soil quality regeneration by grass-clover leys in arable rotations compared to permanent grassland: Effects on wheat yield and resilience to drought and flooding
Soil quality regeneration by grass-clover leys in arable rotations compared to permanent grassland: Effects on wheat yield and resilience to drought and flooding
复制标题
DOI：
10.1016/j.still.2021.105037
复制
发表时间：
2021-05-08
影响因子：
6.5
通讯作者：
Leake，Jonathan R.
中科院分区：
文献类型：
--
作者：
Berdeni，Despina;Turner，Anthony;Leake，Jonathan R.
集约化耕作消耗了土壤有机碳和蚯蚓，导致大孔隙的丧失，破坏了水文功能，限制了作物产量，加剧了干旱和洪水的影响，而干旱和洪水正随着气候变化而加剧。人们普遍认为，传统上以耕地轮作（ley）方式种植的草和豆类混合物可以恢复土壤功能，但令人惊讶的是，关于它们对土壤特性、对极端降雨的适应能力和作物产量的影响的证据有限。利用从4块集约种植的耕地、19个月大的草-三叶草草甸带和3块相邻的永久草地采集的表层土壤样本，研究了茎伸长期间4周的洪水、干旱或环境降雨对土壤性质和小麦产量的影响。与耕地相比，在洪水和环境条件下，轮作土壤增加了蚯蚓数量、入渗速率、大孔隙流量和饱和导电性，降低了压实（体积密度），使小麦产量提高了42 - 95%。土壤有机碳、全氮、持水量和干旱条件下的粮食产量与耕地对照差异不显著（P < 0.05），但与耕地对照相比表现为不完全恢复。总体而言，草-三叶草轮作使蚯蚓种群再生，逆转了集约耕作土壤的结构性退化，促进了免耕种植的采用，打破了耕作驱动土壤退化的循环。人工林对水文功能的实质性改善将有助于减少洪水和水污染风险，潜在地证明为这些生态系统服务付费是合理的，特别是从长期来看，人工林增加了土壤碳固存。
Intensive arable cropping depletes soil organic carbon and earthworms, leading to loss of macropores, and impaired hydrological functioning, constraining crop yields and exacerbating impacts of droughts and floods that are increasing with climate change. Grass and legume mixes traditionally grown in arable rotations (leys), are widely considered to regenerate soil functions, but there is surprisingly limited evidence of their effects on soil properties, resilience to rainfall extremes, and crop yields. Using topsoil monoliths taken from four intensively cropped arable fields, 19 month-old grass-clover ley strips in these fields, and from 3 adjacent permanent grasslands, effects on soil properties, and wheat yield in response to four-weeks of flood, drought, or ambient rain, during the stem elongation period were evaluated. Compared to arable soil, leys increased earthworm numbers, infiltration rates, macropore flow and saturated hydraulic conductivity, and reduced compaction (bulk density) resulting in improved wheat yields by 42–95 % under flood and ambient conditions. The leys showed incomplete recovery compared to permanent grassland soil, with modest gains in soil organic carbon, total nitrogen, water-holding capacity, and grain yield under drought, that were not significantly different (P> 0.05) to the arable controls. Overall, grass-clover leys regenerate earthworm populations and reverse structural degradation of intensively cultivated arable soil, facilitating adoption of no-tillage cropping to break out of the cycle of tillage-driven soil degradation. The substantial improvements in hydrological functioning by leys will help to deliver reduced flood and water pollution risks, potentially justifying payments for these ecosystem services, especially as over longer periods, leys increase soil carbon sequestration.