Abstract
The aim of this study was to evaluate the influence of different grass cultivars on physical attributes of an Oxisol in the Agreste region of Paraíba. The experiment was set up in 2005 in experimental areas of the Center of Agricultural Sciences of the Federal University of Paraíba, Areia-PB. The experimental design adopted was that of randomized complete blocks (RCB) with 5 treatments and 4 replications, in experimental plots of 50 m2. The treatments were the following: I. Brachiaria decumbens Stapf., II. Brachiaria brizantha, III. Brachiaria humidicola (Rendle) Schweickvr., IV. Brachiaria brizantha cv. MG5-Vitória and V. Brachiaria ruziziensis. In October 2018 samples of soil with disturbed and undisturbed structure were collected at the center of each experimental plot in the depth of 0.0-0.10 m for the determination of the following variables: soil porosity (total, macro and micro), bulk density, compaction degree, saturated hydraulic conductivity, field capacity, permanent wilting point, available water content, soil aeration capacity, clay dispersed in water, flocculation degree and aggregate stability index. The analysis of variance was performed and the means were compared by Tukey’s tests, principal component analysis and Pearson’s correlation analysis (p < 0.05). It is concluded that after the 13-year period, Brachiaria brizantha promoted improvements to the field capacity of the Oxisol. The other attributes were not physically altered. Main component analysis showed that the correlation values were more significant for the Brachiaria brizantha component. Pearson’s correlation was significant between field capacity and soil aeration capacity.
Highlights
The land usage and management system, when performed incorrectly can alter the physical attributes of the soil, promote degradation, reduce quality and cause damage to its sustainability
The samples with preserved structure were collected at the center of each experimental plot. They were taken to the Laboratory of Soil Physical Analysis of the Center of Agricultural Sciences of the Federal University of Paraíba to determine the following attributes: Total porosity (TP), microporosity and macroporosity (Mi & Ma), soil aeration capacity (SAC), bulk density (BD), compaction degree (CD), field capacity, permanent wilting point, available water content, saturated hydraulic conductivity (Kθ),weighted meansdiameter of wet and dry aggregates (WMDda ad weighted meansdiameter of soil wet aggregates (WMDwa)), aggregate stability index (ASI), clay dispersed in water (CDW) and flocculation degree (FD), as described in Teixeira et al (2017)
There was no significant statistical variation for total porosity (TP) (p < 0.05) level between the assessed treatments (Table 3), the values varied from 0.44 m3 m-3 in the Brachiaria ruziziensis treatment to 0.49 m3 m-3 in the Brachiaria decumbens Stapf. treatment
Summary
The land usage and management system, when performed incorrectly can alter the physical attributes of the soil, promote degradation, reduce quality and cause damage to its sustainability. Different attributes have been used to evaluate soil physical quality, such as: bulk density, macroporosity, microporosity, total porosity, aggregates stability, soil penetration resistance (Lima et al, 2014) and saturated hydraulic conductivity, for being a parameter of great importance in the water movement through the soil (Soto & Kiang, 2018). In production systems where vegetation cover is suppressed, changes in soil physical attributes occur, reducing the sustainability of agricultural production, especially in environments with climatic irregularities. In this context, it is noted an urgent need to adopt management systems that maximize food production, without compromising the physical properties of the soil. The maintenance of the vegetation cover has been used in a quite satisfactory way in conservationist production systems, considering the physical improvements that it promotes in the soil, especially in situations of low water availability (Costa et al, 2007; Oliveira et al, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
