Changes in soil chemical and physical properties in pasture fertilised with liquid swine manure

Abstract

Chemical and physical properties of soil can be altered with the successive application of liquid swine manure (LSM), also known as slurry. Therefore, monitoring the impact of LSM is essential to an assessment of the potential agronomic and environmental benefits and risks associated with management practices. The aim of this study was to evaluate the effects of LSM on the chemical and physical attributes of soil under pasture (Cynodon spp.), located in southern Brazil. Four areas were sampled: three areas cultivated with Cynodon spp. pasture with successive applications of 200 m 3 ha -1 y -1 of LSM for three, eight and 15 years; and untreated native forest as a reference. The soil attributes evaluated were: organic carbon (OC), active (pH water) and potential acidity (H + Al + 3 ), nutrient availability (i.e., P, K, Ca, Mg, Cu and Zn), soil bulk density, macro, micro and total porosity. Successive applications of LSM on pasture reduced soil active acidity, and increased the soil organic C and plant-available N, P, Ca, Mg, Cu and Zn contents. These effects were more intense with time and in the shallowest layers, i.e. 0-10 cm.Excessive increases in P, Cu and Zn in the soil should be carefully monitored to minimize the contamination risks to soil, ground and surface waters. Soil physical attribute changes were more associated with land use (pasture versus native forest) than LSM use, and LSM applications induced slight improvements in the soil structural quality over time.

Use of Swine Manure in Agriculture in Southern Brazil: Fertility or Potential Contamination?

“…This distribution changes when assessing the effect of manure in comparison to applications with mineral fertilizers, changing to close to 40 those in which the MOS content increased and 60% in those in which there was no effect. The positive effect of SM on SOM was observed by Scheid et al [12] with an increase in the organic C content of a Hapludox in pasture area (Cynodon spp.) after 15 years of PS applications with the dose of 200 m 3 ha −1 year −1 , in Nova Candelária, RS.…”

“…SM applications promote nutrients added to the soil, increasing its contents and, consequently, its availability to plants [6,[32][33][34][35][36][37]. Naturally, SM applications allow a more complete nutrients fertilization, not limited to N, K, and P, present in high concentrations in the manure, but also adding other macro and micronutrients, such as Ca, Mg, Cu, Zn, and Mn [7,9,12]. In a study conducted by Pessotto et al [34] in the municipality of Três Passos, RS, in a Entisol, PS applications (150 m 3 ha −1 ) for four and 16 years in pasture areas (Cynodon spp.)…”

“…Additionally, the addition of solid material, such as PS compost or DL, tends to promote the greater accumulation of organic C than PS applications, due to the higher C content in these solid manures [6,7]. The increase in SOM contents in soils fertilized by SM is a factor of great importance in increasing soil fertility, contributing to its CEC, microbiological activity, and soil structure, also is an attribute associated with soil quality [11,12]. However, it is important to notice that some studies have also shown the null effect of SM application on SOM contents [7,16,33].…”

“…Studies carried out in these Brazilian states have shown that SM are rich sources in macro and micronutrients, and their beneficial use for plant growth and development, serving as an interesting alternative in the partial or total replacement of mineral fertilizers, promoting the maintenance of productivity and decrease in external inputs in agricultural production areas [2,5,9,10]. In addition, SM applications in agricultural areas promotes benefits to different soil properties, increasing soil fertility, improving soil structure and microbiological activity [4,6,9,11,12].…”

Production and nutritional value of Mombaça grass with application of whey as an alternative nitrogen source

“…Organic waste can change the chemical and physical properties of the soil, and its use in agriculture can be important from an environmental and economic point of view, favoring the sustainability of agricultural production systems (Carnier et al, 2019;Scheid et al, 2020).…”