Division of Applied Life Science (BK 21+ Program), Gyeongsang National University, Jinju 52828, South Korea.
Division of Applied Life Science (BK 21+ Program), Gyeongsang National University, Jinju 52828, South Korea; Institute of Agriculture and Life Sciences, Gyeongsang National University, Jinju 52828, South Korea.
Sci Total Environ. 2021 Sep 15;787:147503. doi: 10.1016/j.scitotenv.2021.147503. Epub 2021 May 4.
Winter cover crop cultivation and its biomass recycling as green manure (GM) were accepted as an ideal nutrient management practice in temperate organic farming fields. Since its biomass growth was boosted with air temperature rising from late Spring to early Summer, this stage overlapped with cash crops' seeding or transplanting. Thus, organic farmers were suffering from low crop productivity, due to delayed mineralization of incorporated biomass. To accelerate the mineralization of biomass nutrients and control weeds, plastic film mulching (PM) was broadly utilized in organic farming fields of temperate-monsoon climate region. However, the effect of PM on increasing nutrient use efficiency was not properly quantified in GM amended soil. To determine the effect of PM on crop productivity and nutrient use efficiency in GM amended soils, PM and no-mulching treatments were installed under different levels of GM biomass amended soils (0, 25, 50 and 100% of harvested aboveground biomass). The biomass productivity of barley and hairy vetch mixture as cover crop and biomass nitrogen productivity were dramatically increased from the mid May to the early June. PM significantly improved soil temperature and moisture regimes during maize cropping seasons, and then increased inorganic N (NH and NO) contents in soils. These improved soil properties under PM highly increased maize productivity and nitrogen use efficiency (NUE). Comparing with no-mulching, as GM application level was increased, the effect of PM on increasing maize productivity became greater, but its effect on increasing NUE became smaller. In conclusion, PM could be very useful tool to improve productivity and NUE of cash crop maize in organic cropping fields, in which the harvesting time of GM biomass might be sustained to increase GM biomass productivity.
冬季覆盖作物的种植及其生物量作为绿肥（GM）的回收，被认为是温带有机农业领域中一种理想的养分管理实践。由于其生物量的生长随着春末到初夏气温的升高而增加，这个阶段与经济作物的播种或移栽重叠。因此，由于掺入的生物量的矿化延迟，有机农民面临着作物生产力低下的问题。为了加速生物质养分的矿化和控制杂草，在温带季风气候区的有机农业田中广泛使用了塑料薄膜覆盖（PM）。然而，PM 对提高 GM 改良土壤中养分利用效率的影响尚未得到适当的量化。为了确定 PM 对 GM 改良土壤中作物生产力和养分利用效率的影响，在不同水平的 GM 生物质（收获地上生物量的 0%、25%、50%和 100%）下安装了 PM 和无覆盖处理。作为覆盖作物的大麦和毛野豌豆混合物的生物量生产力以及生物量氮生产力从 5 月中旬到 6 月初显著增加。PM 显著改善了玉米种植季节的土壤温度和水分状况，从而增加了土壤中的无机氮（NH 和 NO）含量。PM 下这些改善的土壤特性极大地提高了玉米的生产力和氮利用效率（NUE）。与无覆盖相比，随着 GM 施用量的增加，PM 对提高玉米生产力的效果变得更大，但对提高 NUE 的效果变得更小。总之，PM 可以成为提高有机作物田中经济作物玉米生产力和 NUE 的非常有用的工具，其中 GM 生物量的收获时间可以延长以提高 GM 生物量的生产力。
