Use Of Cover Plants Research Articles

A Community Capitals Assessment of Climate Adaptations to Traditional Milpa Farming Practices in Mayan Communities of Southern Belize

Climate change has exacerbated food and livelihood insecurity for Mayan milpa farmers in Central America. For centuries, milpa farming has been sustainable for subsistence; however, in the last 50 years, milpas have become less reliable due to accelerating climate change, resource degradation, declining markets, poverty, and other factors. Increasing climate-smart agriculture (CSA) practices may be needed. Using interviews with extension leaders and milpa farmers in Belize, this qualitative study examines the capacity for increasing CSA aspects of existing traditional milpa practices, specifically no-burn mulching, soil enrichment, and the use of cover plants. Applying a modified Community Capitals Framework, this study finds four key capitals were perceived by farmers and agriculture extension leaders as barriers for increasing CSA practices. Recommendations to reduce the key barriers include reinstating markets and crop-buying programs and easing border customs restrictions (Governance-Justice and Financial Capitals), improving roads and cellular access for farmers (Infrastructure Capital), and increasing budgets and resources for agriculture extension services and building farmer capacity for CSA practices of mulching, soil enrichment, and cover plants (Human-Capacity Capital). Reducing barriers to these key capitals can facilitate an increase in milpa CSA practices and crop productivity, promote food and livelihood security, and enable climate resilience of Mayan milpa communities in Belize.

Coverage plants in the management of skeletal coffee

Currently, one of the most used practices in national coffee production is skeletal pruning, to preserve productive capacity, correct plant architecture, minimize the occurrence of diseases, among others. Also, it reduces the plants diameter, exposing the soil to climatic conditions, erosion, loss of moisture and nutrients, negatively affecting the development of coffee. The use of cover plants intercropped with coffee is presented as a technique to avoid and minimize these problems. Therefore, the objective of this research was to evaluate the effect of cover crops on the chemical and physical characteristics of the soil and the skeleton coffee tree. The experiment took place at Fazenda Boa Esperança, city of Serrania, South of Minas Gerais, from October/2017 to December/2018, in randomized blocks, composed of 8 treatments with and without cover crops. Three replicates per treatment were used, totaling 24 experimental plots, each with 14 plants, being the 10 central considered useful for evaluation. The cover crops contributed to the improvement of nutrient contents in the soil, maintained a better level of humidity and milder temperatures providing a greater development to the skeletonized coffee. They also positively influence weed control, but none could suppress all plants present in the research.

Sugarcane root system: Variation over three cycles under different soil tillage systems and cover crops

Machinery traffic combined with soil management processes in the establishment of sugarcane areas degrades the soil structure, limiting root development and yield of the crop. The use of conservation tillage systems and cover crops can reduce such effects and improve its soil physical quality. Therefore, a field study was conducted over three agricultural years to assess the development of the sugarcane root system planted under different soil tillage systems and cover crops during three crop cycles. The study was carried out in 2014 in Ibitinga (São Paulo, Brazil) in an experimental design in split-plot scheme, with three repetitions and three soil tillage systems (no-tillage, minimum tillage and minimum tillage with deep subsoiling) combined with four cover crops (sorghum, millet, peanut and sunn hemp), plus one control treatment consisting of conventional tillage and no cover crop use. The root system attributes (dry biomass, density, volume, length, and surface area) were evaluated every three months during the 2015/2016, 2016/2017, 2017/2018 crop years, in the 0.0−0.2 m, 0.2−0.4 m and 0.4−0.6 m layers. Although few significant differences were obtained in the root system of the sugarcane between the different soil tillage systems and use of cover plants, the accumulation of roots was evidenced during the second cycle of the crop, mainly due to the contribution of new roots, arising from the ratoons of the plants. Differences in the dry biomass of the roots were obtained in the minimum and minimum tillage with deep subsoiling, only at the time of harvesting the first crop cycle (cane plant, 395 days after planting) and in the second cycle, 665 days after planting. The highest concentration of root dry biomass was obtained in the 0.0−0.2 m surface layer, containing between 36 % and 62 % of roots. However, the significant differences of root dry biomass between the soil tillage and cover crops occur in the clayey layer at 0.30−0.6 m, where the management effects affected the root system. During the first three sugarcane cycles, the 0.0−0.2 m surface layer concentrated the highest amount of dry biomass of the roots, representing between 36 % and 62 % of the roots present in the first 0.6 m deep.

BIOLOGICAL FERTILIZER AND COVER PLANTS ON SOIL ATTRIBUTES AND MAIZE YIELD

ABSTRACT Maize is an important crop for Brazil's economy. This species is, in general, grown as monoculture, making it necessary the use of conservationist practices for soil management and to favor crop development. The objective of this study was to evaluate the effects of biological fertilizer and cover plants on soil properties and maize yield. The experiment was conducted in a dystrophic Latossolo Vermelho (Oxisol), in the 2015-2016 and 2016-2017 crop seasons in Tangará da Serra, MT, Brazil. The experiment was conducted in a randomized block design, using a double factorial arrangement with an additional control: two biological fertilizer conditions, three soil cover conditions, and a control (forest fragment). Seeds of Pennisetum glaucum and Crotalaria ochroleuca were sowed on October 2015 and 2016. Maize seeds were sowed on December 2015 and 2016, with subsequent application of 150 L ha-1 of biological fertilizer. The soil cultivated with maize had greater chemical quality than that under the forest fragment, however, the forest fragment soil had greater microbiological quality. The use of biological fertilizer and cover plants increased the fertility and microbiological quality of the soil cultivated with maize. The use of cover plants increased the maize yield in both crop seasons. The use of biological fertilizer and soil cover plants (P. glaucum and C. ochroleuca) improved the soil chemical and microbiological quality.

Duration of the effects of scarification and raised bed associated with vegetation cover on soybean yield on an Alfisol

Abstract: The objective of this work was to determine the duration of the effects of the mechanical interventions scarification and raised bed on soybean (Glycine max) grain yield on an Alfisol, as well as to evaluate, through physical indicators, if the use of cover plants during winter increases the duration of these effects. The experimental design was a complete randomized block with four replicates. Two factors were evaluated. The first consisted of types of soil preparation systems: SC14, scarification in November 2014; SC15, scarification in November 2015; RB14, raised bed built in November 2014; and RB15, raised bed built in November 2015. The second consisted of the type of cover crop used: winter fallow, oat, ryegrass, and wheat. From November 2015 to April 2016, soybean was cultivated under the different soil preparation systems. Soil density, total porosity, macroporosity, microporosity, soil saturated hydraulic conductivity, soil resistance to mechanical penetration, and soybean grain yield were evaluated. There was no effect of cover plants after one crop season on the maintenance of soil physical attributes. Changes in soil density, total porosity, and resistance to mechanical penetration, promoted by scarification, are noticeable up to at least 18 months. The continuance of these modifications reflects in soybean grain yield in the second harvest.

Compaction and Physical Attributes of the Soil After the Development of Cover Plants

Compaction problems in heavily tilled soils have been commonly mitigated with the use of cover plants. Aiming to evaluate the effects of compaction on the physical properties of a plyntic Haplic-Alitic Cambisol soil after development of different cover crops, a complete randomized blocks design experiment, with 3 × 3 factorial arrangement and four replications, was conducted. Treatments consisted of cultivation of two legume species, crotalaria (Crotalaria juncea L.) and stylosanthes cv. Campo Grande (Estilosantes capitata + Estilosantes macrocephala) and a grass species, brachiaria (Urochloa brizhantha cv. Marandu), subjected to soil compaction: CM–Conventional soil management (tillage) without additional compaction; CMc4 and CMc8–conventional soil management with additional compaction using a 6 Mg tractor in four and eight wheel passes. Conventional management with additional compaction does not affect significantly the physical attributes at a soil depth of 0.10-0.20 m, and only the soil moisture does not differ according to the soil management, irrespective of the depth and kind of cover plant. Traffic levels in four passes result in an increased soil bulk density and macroporosity in the 0.0-0.05 m, and in soil resistance to penetration and total porosity in the layer up to 0.10 m. Cover crops are important in maintaining soil physical quality to reduce the negative effects of compacting forces, especially to stylosanthes cv. Campo Grande that provided greater soil protection in systems with or without addition of compaction, conditioning the lowest values of bulk density and soil resistance to penetration.

Bulk Density in Jack Bean’s Development Grown in Cerrado Oxisol

The use of cover plants promotes the recycling of nutrients and the increase in organic mass, and minimizes the effects of erosion. The objective was to evaluate the effect of bulk density in the development of jack bean (Canavalia ensiformis) in Cerrado Oxisol. The experiment was conducted in a greenhouse at the Federal University of Mato Grosso, Rondonopolis-MT, in the period from June to September 2013. Oxisol was used from a Cerrado reserve area, collected at 0 - 0.20 m depth. The experimental design was completely randomized, corresponding to bulk density levels (1.0, 1.2, 1.4, 1.6 and 1.8 Mg&middotm-3), and five replications. The experimental plot consisted of three PVC rings (polyvinyl chloride) with 150 mm internal diameter, 300 mm total height, where the upper and lower rings of pots were filled with 1.0 Mg&middotm-3 density soil and intermediaries according to bulk density treatments. The results were submitted to variance analysis and, when significant, to regression analysis, both with a 5% probability, using SISVAR software. At 60 days after germination, number of leaves, stem diameter, plant height, dry mass of leaves, stem dry mass, dry mass of roots, dry mass of nodules, number of nodules and chlorophyll index (SPAD index) were evaluated. The increase in bulk density negatively influences the development of jack bean, showing little efficiency as a decompacting plant in Cerrado Oxisol.

Winter cover crops, plant biomass production and soil resistance

This study aimed to compare results obtained with winter cover plants, in its first crop cycle, in the resistence to soil physical properties and biomass productivity of the plant. Four species of soil cover plants were used: vetch (Vicia sativa L.), radish (Raphanus sativus L.), ryegrass (Lolium multiflorum Lam) and black oat (Avena strigosa Schreb). It was developed in Guarapuava, PR, in the CEDETEG Campus of the Midwestern State Universisty (UNICENTRO). It was carried out the monitoring of a cycle of these crops in the fall/winter of 2010. The soil resistence data were obtained with the penetrometer of impact in its period of greatest development (flowering). It was observed that the use of cover plants in its first crop cycle did not promote changes in soil penetration resistance. The crops of radish presented the best production of vegetal biomass.

Chemical composition of cover plants and its effect on maize yield in no-tillage systems in the Brazilian savanna

The use of cover plants is an important agricultural practice in no-tillage systems. Soil cover and nutrient recycling depend on the dynamics of plant residue decomposition. The objective of this study was to evaluate the effect of the chemical composition and decomposition rates of cover plants on maize yield in no-tillage systems in the savannah, central Brazil. Levels of hemicellulose, cellulose, and lignin, along with decomposition rates of the following plant species were determined at flowering and maturation: Urochloa ruziziensis, Cajanus cajan, Canavalia brasiliensis, Crotalaria juncea, Mucuna aterrima, Pennisetum glaucum, Raphanus sativus, Sorghum bicolor, and Triticum aestivum. Spontaneous vegetation growth in the fallow was used as a control. The highest dry matter yields were obtained from Sorghum bicolor, followed by P. glaucum, when harvested at maturation. Canavalia brasiliensis and U. ruziziensis, the species with lowest lignin levels, presented faster decomposition and lower half-life values compared with the residues of C. cajan and S. bicolor. Cover plants with the lowest lignin concentrations, and thus the fastest residue decomposition rates, such as C. brasiliensis, U. ruziziensis, and P. glaucum, resulted in higher maize yields. Urochloa ruziziensis and C. brasiliensis contributed to nutrient recycling due to their faster decomposition, while C. cajan aids in the formation of soil cover due to slower decomposition of its residues.

Characterization by solid-state CPMAS 13C NMR spectroscopy of decomposing plant residues in conventional and no-tillage systems in Central Brazil

The Savanna region of Central Brazil is currently the most important area for grain production in the country but intensive agricultural activities are related to high losses of soil organic carbon. No-tillage systems were introduced in the mid 1980’s but the use of cover plants in no-tillage systems is poorly studied and there is a demand for selection of suitable species to improve soil organic carbon. This study characterizes the chemical composition of decomposing plant residues of different cover plants ( Crotalaria juncea, Canavalia brasiliensis, Cajanus cajan, Mucuna pruriens, Helianthus annuus, Pennisetum glaucum, Raphanus sativus and natural fallow, as a control). Cover plants were used in rotation with maize, under conventional and no-tillage systems. Decomposition rates were estimated using litter bags and residues of C. juncea, C. brasiliensis, M. pruriens and R. sativus were analyzed by CPMAS 13C NMR. The highest decomposition rates were found for C. brasiliensis and C. juncea, while the lowest for M. pruriens, C. cajan and P. glaucum. C. cajan presented the lowest content of polysaccharides and along with M. pruriens, the highest percentage of aromatic C, reflecting the slow decomposition of highly lignified material. The residues of these two species also presented high hydrophobicity, as a consequence of the presence of aromatic groups. Incorporation of plant residues accelerated the decomposition in comparison to no-tillage system. C. cajan, P. glaucum and M. pruriens are more appropriate to increase soil cover due to lower decomposition rates while C. brasiliensis, R. sativus and H. annus, which presented higher decomposition rates, are indicated for an improvement of nutrient availability.