Decomposition can assume an important role in soil fertility management, underlying techniques that optimize the use of nutrients of plant residues. The objective of this study was to estimate the decomposition rate and nutrient release from cover crop residues in a passion-fruit plantation. The evaluated species were Canavalia ensiformis, Arachis pintoi, Macroptilium atropurpureum, Pueraria phaseoloides and Brachiaria brizantha. Litter decomposition was measured using nylon, 2.0 mm mesh, litter bags during 140 days. The single exponential model adjusted best for all cover crop […]

The increasing need for food, space and other conditions for human survival generate greater anthropic interferences with the environment. Intensively and improperly tilled soils are degraded and illegal civil construction in rural areas is causing problems. Different techniques are being used to ameliorate these soils, mainly by the addition of organic matter, but information on the time required for soil recovery, influence of the organic matter type and on indicators of soil alterations is still rare. Our study aimed to […]

Soil fertility levels in the Agreste region, state of Paraíba, Brazil are generally low. Usually, animal manure is applied to soils to supply agricultural crops with nutrients. However, depending on the quality of the manure applied, incorporation can lead to soil nitrogen immobilization in the beginning of the growing season. It was hypothesized that planting and incorporating crotalaria (Crotalaria juncea) together with animal manure could synchronize the nutrient mineralization pattern more specifically with crop demand. In 2003, field and green-house […]

In untilled soils with green manure cultivation in during the dry season and the management of the nitrogen fertilization usually change the dynamics and the recovery of the nitrogen in the soil-plant system. The objective of this study was to evaluate the amount of native soil nitrogen absorbed by corn under no-tillage and submitted to different N rates in succession to sunnhemp (Crotalaria juncea), millet (Pennisetum americanum) and fallow in a Red Latosol in the Cerrado. The experiment was carried […]

Several studies reveal that the substitution of native vegetation by agricultural systems results in decreases in the C and N soil organic matter pools. Aiming to test the hypothesis that management practices favoring organic residue inputs promote increases in the most sensitive organic matter pools, the present study intended to study areas of an organic management system of acerola fruit production and a conventional cultivation area cropped with carrot and beet in crop rotation with corn. These areas belong to […]

Soil degradation under cultivation results mainly from the inadequate management and it reflects in low crop yields. With the purpose of evaluating the effect of legumes on physical attributes and organic carbon content of an Alfisol, an experiment was conducted in the Alagoinha County-PB, Brazil, between 1997 and 1999, with the following species: Crotalaria juncea L, Cajanus cajan L, Cajanus cajan (L) Millsp, Calopogonium mucunoides L, Canavalia ensiforme L, Dolichos lab lab L, Pueraria phaseoloides L, Macroptilium atropurpureum L, Leucaena […]

The dynamics of nitrogen in soils under no-tillage in Southern Brazil are poorly studied so far. A field experiment on a typic Hapludalf on the experimental area of the Soil Science Department, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil, was carried out in 1998/99 and 1999/00 to evaluate the effect of single crop and mixtures of black oat (BO) (Avena strigosa Schieb), common vetch (CV) (Vicia sativa L.) and oilseed radish (OR) (Raphanus sativus […]

No-tillage has been increasingly adopted by farmers in South Brazil and it has increased the interest for the mixtures of cover crops in the autumn/winter as source of nitrogen to the corn in succession. A field experiment was carried out on a typic Hapludalf at the experimental area of the Soil Science Department, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil, in 1998/99 and 1999/00 to evaluate the effect of single crop and mixtures of […]

A long-term field trial was carried out in the Jaboticabal county, São Paulo State. with the objective of estimating production system effects on the soil organic carbon and soil organic matter fractions. The tested treatments were corn under conventional sowing in the summer and no-tillage in the winter (C-Mi-P), maize under direct sowing in the summer and no-tillage in the winter (D-Mi-P), maize under direct sowing in the summer, Mucuna aterrina as green manure in the winter (D-Mi-Mu), maize under […]

Tropical soils under continuous cultivation undergo fast degradation, leading to crop production decline, mainly due to erosion and reduction of soil organic matter levels. Soil protection with live mulching is one of the alternatives to alleviate these effects and to control soil degradation. This study was conducted to evaluate the root distribution and morphology of three perennial herbaceous leguminous species, as well as its effects on soil aggregation and organic carbon content when used as live mulching. The experiment was […]