Impact of ruzigrass use on soil physical quality for soybean root deepening

• Grant number: 23/10427-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2023
• End date: February 28, 2025
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Moacir Tuzzin de Moraes
• Grantee: Matheus Batista Néri Pereira
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The presence of biopores and root canals in the soil profile can mitigate the effect of soil compaction on soybean root growth. Cropping systems, based on pre-crops with abundant root systems can favor root deepening of grain-producing crops, increasing soil volume and available water, which can improve soil physical quality in no-till production systems. The objective is to evaluate the root deepening of soybean in the absence and presence of ruzigrass (Urochloa ruziziensis). A long-term experiment with soybean cultivation in succession to brachiaria or fallow will be analyzed. The soybean root system and soil physical, chemical and biological samples will be collected in layers (9) up to 200 cm depth (0-10, 10-20, 20-30, 40-50, 70-80, 100-110, 130-140, 160-170 and 190-200 cm). Soybean root quantification will be analyzed using WinRhizo Software. Soil physical evaluation will be carried out for the quantification of permeability (saturated hydraulic conductivity) and water retention properties (soil water retention curve) and pore diameter distribution. The chemical attributes will be evaluated for soil acidity and nutrient availability. The biological attributes will be determined the abundance of bacteria in the rhizosphere, the total C and N content and the enzymes ²-glucosidase, acid phosphatase, and arylsulfatase. The results will be analyzed in the soil profile in isolation for each layer. Principal component analysis (PCA) will be used to explain the variation in the data and determine which soil attributes were the main influencers on root growth at depth (supplementary variables). Therefore, the expected results are that the use of U. ruziziensis favors the deepening of the soybean root system, in layers below 50 cm in the no-tillage system, due to the increase in the amount of biopores in relation to the fallow, with improvement of the physical, chemical and biological quality in the soil profile.