Potential of winter double crops and tillage for managing manure-based nutrient loading

Soil health indicators reveal that past dairy manure applications create a legacy effect

“…In contrast to soil P, pH, electrical conductivity (EC), and NO 3 -N concentrations were not found to be significantly elevated in the manure-treated soils (Table 2). Studies in Idaho have shown that dairy manure generally does not increase soil pH due to the high buffer capacity of alkaline calcareous soils (Baxter et al, 2023;Dungan et al, 2022). With respect to EC, Bierer et al (2023) found that EC increased due to recent manure applications, but in the present study, we found that after 11 years the EC of the manure treatments was similar to the non-manure treatment.…”

“…However, the crops in all treatments had sufficient P according to crop recommendations (Brown et al, 2010;Moore et al, 2012;Robertson & Stark, 2003;Walsh et al, 2019). In a study conducted in southern Idaho, Baxter et al (2023) determined that openlot dairy manures collected from 2015 to 2020 contained 6 g P kg −1 on average (range = 4.5-7.8 g P kg −1 ). Due to the immobile nature of P, it can accumulate in soils when manure P is applied at rates that exceed plant requirements, thus, P surpluses can be expected to persist for long periods of time (Leytem & Mutegi, 2019;Leytem et al, 2021).…”

“…In the semiarid environment of Lethbridge, Canada, Lupwayi et al (2019) reported that increased enzyme activities could be detected decades after the last beef cattle manure application, with significantly greater microbial biomass and enzyme activity under irrigated versus rainfed conditions. Other research conducted in irrigated croplands in Idaho has demonstrated that soils receiving dairy manure have different soil chemical properties and crop yields and quality compared to non-manured soils (Baxter et al, 2023;Robbins et al, 1997).…”