Effect of Nutrient Management Planning on Crop Yield, Nitrate Leaching and Sediment Loading in Thomas Brook Watershed

Abstract

Government priorities on provincial Nutrient Management Planning (NMP) programs include improving the program effectiveness for environmental quality protection, and promoting more widespread adoption. Understanding the effect of NMP on both crop yield and key water-quality parameters in agricultural watersheds requires a comprehensive evaluation that takes into consideration important NMP attributes and location-specific farming conditions. This study applied the Soil and Water Assessment Tool (SWAT) to investigate the effects of crop and rotation sequence, tillage type, and nutrient N application rate on crop yield and the associated groundwater [Formula: see text] leaching and sediment loss. The SWAT model was applied to the Thomas Brook Watershed, located in the most intensively managed agricultural region of Nova Scotia, Canada. Cropping systems evaluated included seven fertilizer application rates and two tillage systems (i.e., conventional tillage and no-till). The analysis reflected cropping systems commonly managed by farmers in the Annapolis Valley region, including grain corn-based and potato-based cropping systems, and a vegetable-horticulture system. ANOVA models were developed and used to assess the effects of crop management choices on crop yield and two water-quality parameters (i.e., [Formula: see text] leaching and sediment loading). Results suggest that existing recommended N-fertilizer rate can be reduced by 10-25 %, for grain crop production, to significantly lower [Formula: see text] leaching (P > 0.05) while optimizing the crop yield. The analysis identified the nutrient N rates in combination with specific crops and rotation systems that can be used to manage [Formula: see text] leaching while balancing impacts on crop yields within the watershed.

Impact of conservation tillage on nitrogen and phosphorus runoff losses in a potato crop system in Fuquene watershed, Colombia

“…However, the results are found to vary significantly and provide important insights only for particular agricultural watersheds (Park et al, 2014;Amon-Armah et al, 2013;Liu et al, 2013;Bosch et al, 2013;Betrie et al, 2011;Lam et al, 2011). Despite the increased use of modeling tools to assess the impact of CT as an agricultural BMP on the pollutant losses, there are still knowledge gaps in this topic.…”

Impacts of no-tillage management on nitrate loss from corn, soybean and wheat cultivation: A meta-analysis

“…While several studies have documented positive effects of NT in reducing NO 3 − concentration in groundwater 4 , 13 , other studies have found no effect 14 , 15 . Many variables, including physical (e.g., rainfall variability, soil texture) and management factors (e.g., crop species, fertilizer type, tillage duration) likely affect NO 3 − mobility and export from agricultural fields 16 . Changes in rainfall intensity, in particular, can influence the amount of NO 3 − carried into the waterways as they affect the amount of water leaving the system 10 .…”

Meta‐Analysis of Phosphorus Loss from No‐Till Soils

“…Variable effects of NT on soil P loss have been reported, likely due to the various physical (e.g., transport pathway, rainfall variability) and management factors (e.g., crop species, tillage duration) affecting P transport in agricultural landscapes (Amon‐Armah et al, 2013). Surface transport primarily consists of runoff, which involves interactions of water with nutrients in the surface soil layers.…”