Biomass decomposition and nutrient release from black oat and hairy vetch residues deposited in a vineyard

Abstract

A significant quantity of nutrients in vineyards may return to the soil each year through decomposition of residues from cover plants. This study aimed to evaluate biomass decomposition and nutrient release from residues of black oats and hairy vetch deposited in the vines rows, with and without plastic shelter, and in the between-row areas throughout the vegetative and productive cycle of the plants. The study was conducted in a commercial vineyard in Bento Gonçalves, RS, Brazil, from October 2008 to February 2009. Black oat (Avena strigosa) and hairy vetch (Vicia villosa) residues were collected, subjected to chemical (C, N, P, K, Ca, and Mg) and biochemical (cellulose - Cel, hemicellulose - Hem, and lignin - Lig content) analyses, and placed in litter bags, which were deposited in vines rows without plastic shelter (VPRWS), in vines rows with plastic shelter (VPRS), and in the between-row areas (BR). We collected the residues at 0, 33, 58, 76, and 110 days after deposition of the litter bags, prepared the material, and subjected it to analysis of total N, P, K, Ca, and Mg content. The VPRS contained the largest quantities and percentages of dry matter and residual nutrients (except for Ca) in black oat residues from October to February, which coincides with the period from flowering up to grape harvest. This practice led to greater protection of the soil surface, avoiding surface runoff of the solution derived from between the rows, but it retarded nutrient cycling. The rate of biomass decomposition and nutrient release from hairy vetch residues from October to February was not affected by the position of deposition of the residues in the vineyard, which may especially be attributed to the lower values of the C/N and Lig/N ratios. Regardless of the type of residue, black oat or hairy vetch, the greatest decomposition and nutrient release mainly occurred up to 33 days after deposition of the residues on the soil surface, which coincided with the flowering of the grapevines, which is one of the phenological stages of greatest demand for nutrients.

Nutrient Release during Residue Decomposition of Weeds Mown at Different Times in a Persimmon Orchard

“…DM decomposition might have been promoted by rising air temperature and by rainfall in summer [6] [15] [16]. High temperature and rainfall affect microbial activity and the removal of soluble compounds, increasing decomposition and consequent reduction in residual DM [12] [17].…”

“…In hairy vetch, most nutrients in the residues may be released in the first 30 days after the residue deposition on the soil surface [6] [9]. However, the nutrient release is negatively correlated with carbon-to-nitrogen (C/N) ratio [11].…”

Cover Crops Effects on Soil Chemical Properties and Onion Yield

“…The high P retention in RY residues may be due to the predominance of organic P forms, which depend on DM mineralization for their release, and RY had the highest t ½ (39 days), as well as the highest lignin levels. The lower content of remaining P in the RD residue can be explained by its low C/P ratio (56) ( Table 1) Ferreira et al, 2014). The intermediate values of remaining P for BO are partly due to their C/P ratio (62), which resulted in an intermediate value in comparison to all other species (Table 1).…”

“…The higher remaining K content in the RY residue can be explained by its high t ½ (90 days) of DM (Table 2), and the high content of non-structural biomass (735.48 g kg -1) ( Table 1). The low contents of remaining K at 30 DAD (Figure 3c) are due to the high solubility of this element in the tissue, since it does not bind to any structural component, which facilitates its quick release (Pavinato and Rosolem, 2008) and high content in the soil (Teixeira et al, 2012;Ferreira et al, 2014).…”

Cover Crops and Nitrogen Fertilization Effects on Nitrogen Soil Fractions under Corn Cultivation in a No-Tillage System

“…However, it is difficult to predict the contribution of N mineralization during the crop cycle; the availability of this nutrient depends on a number of factors including, its mineral forms (nitrate and ammonium) and rapidly mineralized organic forms, which are functions of biotic and abiotic factors, as well as the total N content and the soil C/N ratio, soil moisture and temperature (Knoepp and Vose, 2007;Ferreira et al, 2014).…”