Atributos físicos, químicos e biológicos do solo em cultivo de moringa (Moringa Oleifera Lam.) sob manejo conservacionista no semiárido pernambucano

Abstract

Currently one of the main scientific and technology to mitigate the effects of soil degradation has been the restoration not only of the structure but also of the functioning of the degraded system. However, efforts in this line will only be successful if they can add economic and social benefits and ecological benefits. In an attempt to reverse this scenario, conservation practices are considered alternatives to support a new paradigm based on sustainable development. The objective of this work was to evaluate the spatial-temporal variability of the physical, chemical and biological attributes of the soil and the development of the Moringa (Moringa oleifera Lam) crop under vegetative conservation management technique, mulch (coconut powder). For this, two field experiments were carried out in the semi-arid alluvial valley at the Experimental Station of Irrigated Agriculture of Parnamirim - PE, belonging to the Federal Rural University of Pernambuco. The first experiment was evaluated the effect of mulching and organic fertilization on the soil physical-chemical parameters, soil nematode fauna and development of the Moringa crop under irrigation. The experimental design was completely randomized, with four treatments (presence of mulching (PCM), presence of organic fertilization (PAO), presence of fertilization and mulch (PAOCM) and control); repetition over time (before transplanting, 205 DAT, 332 DAT, 438 DAT, 604 DAT) with five replicates, totaling 20 experimental units. Data were submitted to analysis of variance, with significance levels of 5% for the F test. The Tukey test was used at a 5% probability level. Three areas were selected: one area in the riparian forest (MC), and two adjacent areas with Moringa cultivation under irrigation (one area containing conservation practice using coconut powder as mulch) and another absence of mulching). The obtained data were submitted to descriptive analysis and geostatistical analysis to characterize spatial dependence for semivariograms modeling and elaboration of kriging maps. The determination of the phenological parameters: plant height and stem diameter were carried out in both experiments. The values of soil moisture (w), organic carbon (CO), microbial respirometry (C-CO2) and soil electrical conductivity (EC) were determined. Only the first experiment was evaluated to soil nematode and soil and plant temperature. According to the results, the conservation management technique using mulch (coconut powder) influenced the development of the moringa oleaginous and contributed to the increase of organic carbon in the soil, reducing soil moisture loss and soil temperature. It was observed that there was a significant increase in organic carbon values at the sampling time (205 DAT, 332 DAT and 604 DAT), mainly in the treatment with presence of mulch. Soil organic carbon variations are more evident for the 0.0 - 0.20 m layer, and there were no important variability in the treatment in the absence of mulch. Microbial respirometry with the treatments with and without cover, no evidence of pattern distinction was observed. Plant parasites were dominant among the trophic groups, with presence of Rhabditts, Rhabditidae and Diplogaster nematodes, which have a c-p1 scale, in treatments with presence of mulch, indicating that the area is in a disturbed environment. Nematodes are considered important bioindicators that are influenced by the chemical properties of the soil under field conditions under oleaginous planting. According to the results obtained in the study, the planting of the oilseed was adequately developed in the region, providing new concepts along with conservationist technique to coexist with the soil conditions and water scarcity, increasing the carbon stocks in the soil.