Soil pH and nitrogen changes following cattle and sheep urine deposition

Abstract

The relationship between animal urine deposition and variability in soil chemical composition and crop growth is not well established in the semiarid region of West Africa. This study was conducted to examine the changes over time in soil pH and mineral nitrogen (N) concentrations at the micro sites of cattle and sheep urine patches in comparison to those occurring in fertilizer urea placement zones. The urine and fertilizer solution containing each 400 mg N (800 kg N ha -1 ) were spread onto individual plots covering a surface area of 4-cm radius. The treatments included a control, which consisted of distillate water. Soil samples from three replicate plots were taken in 4-cm increments to a depth of 16 cm and distance of 16 cm on a grid pattern at days 1, 7, 21, 49, 90, 120, and 150 after application. Significant pH and mineral N gradients develop in the vicinity of the fertilizer and urine placement zones declining towards the periphery and the deeper soil layers. The pH at the center of the urine zone remained above 7.5 throughout the 150 days of 1254 SOMDA, POWELL, AND BATIONO the study period. After the initial increase, the soil pH below the fertilizer placement sites declined to the control level by day 90. Concentrations of ammonium (NH 4 ) + nitrate (NO 3 ) also increased markedly in the immediate soil layers of the urine and urea placement zones, and then decreased over time probably due to N losses by volatilization and leaching. Concentrations of mineral N at the periphery of the placement site were similar for all treatments throughout the study period, indicating very little lateral N diffusion. These results provided evidence that animal urine causes significant variabilities in soil chemical composition, even in short distance from the deposition zones. The high soil solution pH in the vicinity of the urine patches alleviate the potential of aluminum (Al) toxicity while increasing the phosphorus (P) availability to crop plants.

Short-term nitrous oxide emissions from pasture soil as influenced by urea level and soil nitrate

“…Urea alone was added rather than artificial cattle urine, since we wanted to avoid the interference from turnover of organic constituents in the urine (Bristow et al, 1992). The absence of hippuric acid probably delayed urea hydrolysis in the soil (Whitehead et al, 1989), thereby dampening the initial increase in pH (Sherlock and Goh, 1984;Somda et al, 1997), as well as the osmotic down-shock. Thus, it is likely that any stresses imposed on soil organisms would be as great or greater in a pasture after deposition of cattle urine.…”

Estimation of nitrogen flow within a village-farm model in Fakara region in Niger, Sahelian zone of West Africa

“…Since data on livestock and human excreta were obtained from secondary sources (Somda et al 1997; Powell et al 1998;Matsumoto et al 2010), uncertainties may be taken into consideration and some possibilities on the variation of results might be expected. Therefore, the actual nitrogen flow in the area focused on in this study may differ from the estimated values.…”

“…For instance, the levels of dry matter produced per day per cow, sheep, and goat were 2,383, 345, and 197 g, respectively (Powell et al 1998). The average amount of individual sheep urine voiding was estimated on the basis of a previous study (Somda et al 1997), and was 64 g per urine voiding, with a total nitrogen level of 2.98 g kg -1 (Powell et al 1998).…”

Changes in soil phosphorus availability and associated microbial properties after chicken farming in Lei bamboo (Phyllostachys praecox) forest ecosystems

“…However, BCF altered the composition of moderately labile P in this study, and 1 M HCl‐Pi gradually dominated with increasing grazing density (Figure 2b). This observation can be linked to three possible phenomena: (a) the deposition of chicken manure gradually increases soil pH with increasing grazing density (Somda, Powell, & Bationo, 1997), which reduces the adsorption performance of iron–aluminum oxides (Yan, Wang, Liu, & Feng, 2019) and prevents it from complexing with more free phosphorus; (b) the stability of HCl‐extracted P is strongly dependent on soil pH, and HCl‐extracted P pools in high‐pH soils tend to contain highly stable calcium phosphate minerals (Helfenstein et al, 2020; Hou, Lu, Jiang, Wen, & Luo, 2019); and (c) the higher Ca 2+ in chicken manure may complex with dissolved Pi in the soil to form 1 M HCl‐Pi (Sugiyama et al, 2016). In synthesis, the P fraction was influenced by grazing density, and an increase in labile and moderately labile P increased the soil P availability and supply capacity in the BCF system.…”