Soil, water, and nutrient losses from management alternatives for degraded pasture in Brazilian Atlantic Rainforest biome

Abstract

The objective of this study was to evaluate sediment, water and nutrient losses from different pasture managements in the Atlantic Rainforest biome. A field study was carried out in Alegre Espiríto Santo, Brazil, on a Xanthic Ferralsol cultivated with braquiaria (Brachiaria brizantha). The six pasture managements studied were: control (CON), chisel (CHI), fertilizer (FER), burned (BUR), plowing and harrowing (PH), and integrated crop-livestock (iCL). Runoff and sediment samples were collected and analyzed for calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P) and organic carbon contents. Soil physical attributes and above and below biomass were also evaluated. The results indicated that higher water loss was observed for iCL (129.90mm) and CON (123.25mm) managements, and the sediment losses were higher for CON (10.24tha) and BUR (5.20tha) managements when compared to the other managements. Majority of the nutrients losses occurred in dissolved fraction (99% of Ca, 99% of Mg, 96% of K, and 65% of P), whereas a significant fraction of organic carbon (80%) loss occurred in a particulate form. Except for P, other nutrients (Ca, Mg and K) and organic carbon losses were higher in coarse sediment compared to fine sediment. The greater losses of sediment, organic carbon, and nutrients were observed for CON followed by BUR management (p<0.05). Our findings indicated that the traditional pasture management adopted in the Atlantic Rainforest needs to be rethought and burned management should be avoided. Based on the water, soil, and nutrient losses from various practices, to reduce pasture degradation, farmers should adopt edaphic practices by applying lime and fertilize to improve pasture growth and soil cover, and reducing soil erosion in the hilly Brazilian Atlantic Rainforest biome.

Distribution of C and inorganic phosphorus fractions in different aggregate sizes under forestry, agroforestry system and pasture

“…The higher values of aggregate stability in the pasture and agroforestry, suggest that by removing the forestry fragment to establish those land uses improved this physical property of the soil (Figure 2 and Table 2). Highest percentage of aggregates higher than 2 mm found in sub-surface pasture is possibly related to the constant renovation of the root system in this vegetation, which directly influences the soil aggregation (Rocha Junior et al, 2017). Similar results were verified by Adesodun et al (2007).…”

“…On the other hand, systems such as agroforestry systems and pastures, or natural systems when well managed or preserved, are alternatives to raise soil carbon (C) and nutrient contents while maintaining or improving their quality in this region (Guimarães et al, 2014;Rocha Junior et al, 2017).…”

Indicadores De Sustentabilidade Com Base Na Qualidade Do Solo E Acúmulo De Fitomassa Em Pastagens Degradadas

“…No Brasil, assim como em outros países no mundo, as pesquisas realizadas sobre o processo de erosão, são restritas a áreas agrícolas e voltadas para o desenvolvimento de práticas de manejo do solo que diminuam os impactos causados por esse problema (ROCHA-JUNIOR et al, 2017). No entanto, há poucos estudos para avaliar os impactos da erosão nas perdas de solo e água em áreas de pastagens (TEAGUE et al, 2010;JEMAI et al, 2013;SHAKESBY et al, 2013).…”

Phosphorus transfer at a small catchment in southeastern Brazil: distributed modelling in different land use scenarios

“…Also, soil and water conservation practices, such as maintaining crop residues on soil surface, contour planting, terraces construction, reduced tillage and no tillage (Didoné, Minella and Evrard, 2017;Le Gall et al, 2016;Rocha Junior et al, 2017), are used in Brazil to control erosion and nutrient transport. In this sense, a P index classification was performed according to Table 4 ( Sharpley;Mcdowell;Kleinman, 2001).…”