The seasonality of nitrate and phosphorus leaching from manure and chemical fertilizer added to a chernozemic soil in Canada

Abstract

Identifying seasons sensitive to nutrient losses could help farmers and policymakers to formulate effective nutrient loss reduction strategies. This long-term study monitored water percolation as well as nitrate (NO 3 -N) and total phosphorus (TP) leaching from liquid swine manure and chemical fertilizer applied to intact core lysimeters in a sandy loam soil in Manitoba, Canada. Water percolation, NO 3 -N, and TP leaching were monitored from 2005 to 2016. Chemical fertilizer showed greater average annual mean water percolation (p = .01), annual flow-weighted mean concentration (FWMC) of NO 3 -N (22 mg L -1 ; p < .001), and annual NO 3 -N leaching (36 kg N ha -1 ; p = .002) compared with the manure treatment (FWMC NO 3 -N, 15 mg L -1 ; NO 3 -N leaching load, 22 kg N ha -1 ). Average annual mean TP loss did not differ between treatments (p = .86). Spring (April-June) was the most sensitive season, when >75% of annual percolation, >80% of annual NO 3 -N, and >68% of annual TP leaching losses occurred from both manure and chemical fertilizer. Annual NO 3 -N and TP leaching increased exponentially with cumulative winter and spring precipitation (control, r 2 = .69; manure, r 2 = .79; chemical fertilizer, r 2 = .63) and decreased with winter and spring air temperatures. The largest spring NO 3 -N and TP leaching losses were observed in 2013, which followed the dry year of 2012, indicating the potential for nutrient flushing. The findings emphasize the need for environmentally sound N and P management strategies in cold North American regions underlain by coarse-textured soils, particularly during the spring season.

Optimizing nutrient management to improve tobacco quality while reducing nutrient losses in tobacco fields

“…3, 5), which is consistent with previous research 34 . In contrast, the CF treatment exacerbated the runoff loss of NO 3 − -N, as it is likely due to the rapid nutrient release from soluble fertilizers 35 .…”