Autumn Maize Intercropped with Tropical Forages: Crop Residues, Nutrient Cycling, Subsequent Soybean and Soil Quality

Abstract

Autumn maize intercropped with tropical forages can raise the amount of crop residues and improve nutrient cycling, favoring subsequent soybean crop. The objective of this study was to evaluate the effect of forms of implementation of intercropping of irrigated autumn maize with tropical forages on yield, decomposition, nutrient accumulation and release, and on the ratio of lignin/total N of forage residues, yield components, and grain yield of subsequent soybean, and on soil physical and chemical properties, under no-tillage in lowland Cerrado. The experiment was arranged in randomized blocks in a factorial (4 × 3 + 1) design with one control and four replications. The treatments consisted of four forages: Palisade grass, Congo grass, and two Guinea grass cultivars (Tanzânia and Áries); and three methods of sowing intercrops of forageautumn maize: forage sown simultaneously with maize in the sowing furrow, mixed with fertilizer; forage sown by broadcasting on the day of maize sowing; and forage seeds mixed with fertilizer broadcast on maize in growth stage V4; plus a control (maize monoculture). The decomposition and nutrient release rate of the forage residues were evaluated by the litter bag method, 30, 60, 90, and 120 days after desiccation. Sowing the forages in the furrow and by broadcasting raise the total amount of maize residues compared to method V4. Regardless of the forage type and sowing methods, intercropping increases the amount of residues compared to maize monoculture. The forages and sowing methods had no influence on nutrient accumulation in the residues at the time of desiccation and at the lowest lignin/total N ratio in Congo grass residues, and a logarithmic decay was observed. Forage and sowing methods did not influence the macronutrient release rate from crop residues for 120 days after desiccation; the release of N, P, K and Mg is logarithmic and the release of Ca and S exponential. Forage and sowing methods do not influence yield components and grain yield of subsequent soybean. However, intercropping increased grain yield of subsequent soybean compared to soybean after maize monoculture, and preserved the soil chemical and physical properties.

Brachiaria and Panicum maximum in an integrated crop–livestock system and a second-crop maize system in succession with soybean

“…When evaluating the release rate of nitrogen, phosphorus and potassium within the mulch biomass of Marandu palisadegrass, Congo grass, Mombaça guinea grass, Tanzania guinea grass and Aries guinea grass, Pereira et al (2016) reported that the maximum release of these nutrients occurred during the first 30 days. In general, at 120 days after planting, more than 60% of the nutrients had already been released from the mulch, and these results are similar to those found in the current study.…”

Soil mechanical scarification increases the dry matter yield of cover crops under no-tillage

“…The growth of isolated cover crops or intercropping systems is promising alternatives to significantly increase dry matter yield and nutrient accumulation in the consolidated NTS (Pereira et al, 2016;Chieza et al, 2017). Plants from Poaceae family such as Pennisetum glaucum, Urochloa ruziziensis and Urochloa brizantha are species of the fast establishment, high dry matter yield, and which are known to promote nutrient cycling (Teixeira et al, 2012;Pereira et al, 2016).…”

“…The growth of isolated cover crops or intercropping systems is promising alternatives to significantly increase dry matter yield and nutrient accumulation in the consolidated NTS (Pereira et al, 2016;Chieza et al, 2017). Plants from Poaceae family such as Pennisetum glaucum, Urochloa ruziziensis and Urochloa brizantha are species of the fast establishment, high dry matter yield, and which are known to promote nutrient cycling (Teixeira et al, 2012;Pereira et al, 2016). Crops from Fabaceae family are also included in production systems, isolated or intercropping with Poaceae plants in the second crop, aiming to increase crop yield in succession, mainly by the availability of nitrogen (Chieza et al, 2017), due to biological nitrogen fixation (BNF), and the low Carbon-Nitrogen (C:N) ratio of the produced straw (Silva et al, 2007;Pacheco et al, 2011).…”

Relationship Among Crop Systems, Soil Cover, and Water Erosion on a Typic Hapludox

“…Combining corn with cover crops has been an intercropping combination effective in improving soil physical properties, controlling water erosion, and reducing organic carbon, nutrient, soil, and water losses (Debarba and Amado, 1997;Spagnollo et al, 2001;Albuquerque et al, 2005;Gilles et al, 2009;Silveira and Stone, 2010;Chen and Weil, 2011;Gabriel and Quemada, 2011;Freitas et al, 2012;Pereira et al, 2016). The benefits of using cover plants were also demonstrated by Gómez et al (2011), who concluded that they significantly reduced water erosion in comparison to traditional tillage practices in Southern France, Spain, and Portugal.…”