Grass Buffer Strips Improve Soil Health and Mitigate Greenhouse Gas Emissions in Center-Pivot Irrigated Cropping Systems

Abstract

Declining water resources and soil degradation have significantly affected agricultural sustainability across the world. In the southern High Plains of USA, buffer strips of perennial grasses alternating with cultivated corn strips were introduced in center-pivot irrigated crop fields to increase agronomic production and ecosystem services. A study was conducted to evaluate soil carbon (C) and nitrogen (N) dynamics, greenhouse gas (GHG) emissions, and soil health benefits of integrating circular grass buffer strips in the center-pivot irrigated corn production system. Multiple parameters were assessed in the grass buffer strips, and at distances of 1.52, 4.57, and 9.14 m away from the edges of grass strips in corn strips. While grasses in the buffer strips depleted N compared to corn strips, potential C mineralization (PCM) was 52.5% to 99.9% more in grass strips than in corn strips. Soil microbial biomass C (MBC) content was 36.7% to 52.5% greater in grass strips than in corn strips. Grass buffer also reduced carbon dioxide (CO2) and nitrous oxide (N2O) emissions from corn strips. Grass buffer strips can improve soil health and sustainability in center-pivot irrigated cropping systems by increasing soil C components and reducing GHG emissions.

Soil health responses of circular grass buffer strips in center‐pivot irrigated agriculture

“…The grasses may have also utilized the applied N fertilizer more efficiently than corn, leaving very little residual inorganic nitrogen in the soil. Previous studies also reported lower inorganic N in the surface soil of the grass buffer than in the corn fields with and without grass buffer (Iqbal et al., 2015; Kim et al., 2022; Mitchell et al., 2015; Salehin et al., 2020).…”

“…In addition, less residual NO 3 − ‐N observed in the grass buffer strip system may have significant implications for fertility management and nitrogen cycling. An earlier study reported significantly lower greenhouse gas emissions in grass strips than in corn strips, suggesting the lower global warming potential of agriculture with grass integration (Salehin et al., 2020). The reduction in N leaching potential and GHG emissions observed in the grass buffer strips and adjacent corn strips may also positively impact the groundwater quality in the region.…”

Soil CO2 emissions in cropland with fodder maize (Zea mays L.) with and without riparian buffer strips of differing vegetation

“…Despite having the largest amount of soil OM, the willow riparian buffer had low CO 2 emissions, which could mean that the treatment had a low labile C fraction similar to other studies including Dlamini et al (2020), but we did not quantify C fractions in the current study. The previous author reported that treatments with highly labile C (readily available for microbial reactions) result to high CO 2 compared to those with less labile C. Soil respiration is an indicator of total soil biological activity, and therefore an indicator of overall soil quality (Tufekcioglu et al 2001;Visser and Parkinson 1992), and vegetated riparian buffers have been reported to improve soil quality characteristics compared to croplands (Salehin et al 2020;Seobi et al 2005;Udawatta et al 2009), thus the resultant higher soil CO 2 emission the grass and woodland riparian buffers compared to the upslope maize and no-buffer control of the current experiment.…”

Fodder Grass Strips for Soil Conservation and Soil Health

“…Soil quality is the fundamental first step to environmental improvement [7], and the introduction of multiple strips of grasses may benefit the adjacent crop strips because pairing grassland into croplands increases SOC, labile C, and microbial biomass [8,9]. Soil quality for the experiment was calculated for each year using 16 physico-chemical and biological soil parameters, e.g., soil organic carbon, available nitrogen, phosphorous, potassium, micronutrients and macronutrients, soil aggregates, infiltration, etc.…”