Soil physical change and sugarcane stalk yield induced by cover crop and soil tillage

Abstract

Conventional tillage and intensive machinery traffic are the major causes of physical soil degradation in sugarcane fields. This study evaluates the impact of adopting conservation management practices during sugarcane planting on soil physical properties and stalk yield of sugarcane in the municipality of Ibitinga, state of São Paulo, Brazil. The experimental design (split-block) included four cover crops and three soil tillage systems, with three repetitions. For comparison purposes, a control treatment was also included (without cover crop and under conventional tillage). Sampling for soil physical analysis was performed in three layers that coincide with soil horizons A (0.00-0.20 m), AB (0.20-0.30 m), and Bt (0.30-0.70 m), during cane-plant and first sugarcane ratoon cycles. The results showed that cultivation of sunn hemp associated with deep subsoiling induced high stalk yield of sugarcane in both production cycles, cane plant (116 Mg ha -1 ) and first ratoon (114 Mg ha -1 ), with a net gain of 11 and 9 Mg ha -1 compared with the control treatment, respectively. However, these results were not sufficient to induce significant differences in sugarcane yield. Nonetheless, the use of sunn hemp and millet, associated with subsoiling (at 0.40 or 0.70 m depth) during sugarcane planting, are promising management strategies to sustain better soil's physical quality when compared to traditional management, conventional soil tillage without cover crops and/or cash crop, as peanuts, that increase the risks of soil compaction and physical degradation.

Soil tillage systems and forms of lime application on soil attribute enhancements in ratoon sugarcane

“…Compared with CT, DT improved macroporosity over the years (Figure 2a,b). This increase was related to the disruption of the soil layer surface by the rotary hoe, which reached a working depth of 0.4 m during bed formation, increasing soil porosity and reducing soil bulk density (Barbosa et al, 2019; Farhate et al, 2022) and SPR (Cherubin et al, 2016; Marasca et al, 2015; Shukla et al, 2021). Although the treatments did not affect TP (Figure 2a,b), studies suggest that high TP is common in clayey soils and mainly reflects micropores, whereas the volume of macropores is usually deficient, which causes problems with water infiltration, gas exchange and reduced root growth (Cintra et al, 1983).…”

“…DT management provided higher porosity, aeration and water distribution along the entire soil profile, allowing better root development (Barbosa et al, 2020; Farhate et al, 2022; Lovera et al, 2021; Marasca et al, 2015). In addition, the increase in sucrose in DT2 can be explained by the improvement of Ca and Mg contents by liming, as previously discussed.…”

“…As a result, sugarcane roots can develop in deeper layers than under conventional tillage. Under controlled traffic, only strips of soil are toiled for furrowing and planting sugarcane (Farhate et al, 2022; Rossetto et al, 2008; Scarpare et al, 2016).…”

Sugarcane cultivation effects on soil physical properties, functions, and related-ecosystem services

“…The use of traffic control techniques, primarily involves an efficient planting project, including parallelism between traffic lines, tires with high-flotation, and the use of autopilot. Soil management practices such as reduced or no-tillage Luz et al, 2022) and cover crops cultivation on sugarcane renewal (Farhate et al, 2022) are efficient strategies to attenuate soil physical degradation, increase soil organic matter, and improve soil structure creating an environment more resistant to physical degradation by external pressure. On the other hand, the better soil physical quality obtained by soil tillage and the use of cover crops can be weakened by the compaction caused in harvesting operations if controlled traffic not be adopted .…”