Disponibilidade de nitrogênio de fontes minerais e orgânicas aplicadas em um Argissolo cultivado com videira

Abstract

Nitrogen availability of organic and mineral sources applied in Sandy Typic cultivated with vineThe objective of this study was to evaluate the nitrogen (N) availability in a soil with history of growing vines and submitted to application of mineral and organic sources of nutrients. In October 2010, samples of a Sandy Typic Hapludalf soil were collected in a vineyard and in a natural pasture soil, in the municipality of Rosario do Sul (RS). The treatments consisted of: natural pasture and vineyard soil as control; vineyard soil + organic compost; vineyard soil + polymer coated urea and vineyard soil + urea. The soils were incubated and subsamples were taken at 0, 38, 70, 102 and 141 days of incubation to determine N-NH 4 + and N-NO 3 -contents. Concentrations of mineral N, net mineralization, N mineralization in relation to the total N and mineral buildup were calculated. In vineyard soils submitted to application of the polymer coated urea and urea, most N mineralization occurred in the initial period. Nitrogen release from the organic compound has better synchronicity with the vine requirements. The soil reserves of total nitrogen potentially mineralized may supply the vine demand for N.

Phosphorus fractions in soil with a long history of organic waste and mineral fertilizer addition

“…Besides the large amount of P supplied through organic sources, the harvesting were carried out only in corn and bean crops, reducing exports of P by crops and contributing to the increases of the contents available. For all these reasons, it is usual to find in the literature an increase in values of available P in the surface layers of soils with pig slurry, cattle manure and soluble mineral fertilizer applications in agricultural areas, especially under no-tillage (Adeli et al 2008;Veiga et al 2012;Sartor et al 2012;Lourenzi et al 2014;Schmitt et al 2014). …”

“…The use of organic waste such as pig slurry manure (PSM), liquid cattle manure (LCM), and swine deep bedding (SDB) has increased over the years in annual crops or cultivation of perennial crops, due to the fertilizer potential of these wastes (Guardini et al 2012;Ciancio et al 2014;Lourenzi et al 2014). Usually, the dose of organic wastes to be applied to the soil is established based on the percentage of dry matter (DM), the concentration of macronutrients such as nitrogen (N), phosphorus (P), potassium (K), and the index of efficiency, which is related to the entire amount of nutrients contained in waste that can be processed from an organic to a mineral form (CQFS-RS/SC 2004).…”

Produtividade de uvas e composição do mosto de videiras ‘Cabernet Sauvignon’ fertilizadas com composto orgânico e ureia

“…Nevertheless, this variable was not evaluated in the present study. But, in addition, greater grape yield may have occurred because organic compost has a small area of contact with the soil surface, which prolongs the release and availability of forms of N in the vineyard soil (MELO et al 2012, LORENSINI et al 2014 and, therefore, one may expect that the grapevine utilizes a greater quantity of the N derived from the organic compost. Nevertheless, it is fitting to report that in this 2008/2009 crop season, the lower release of N from the compost to the soil may have occurred because of the lower volume of rainfall (Figure 1) and, consequently and possibly, of soil moisture, especially in the months after its application up to grape harvest, with the exception of the months of October 2008 and January 2009, in NH3-N through the volatilization which occurs in greater intensity soon after its application on the soil surface (LORENSINI et al 2012).…”

“…Some studies have shown that this practice can minimize NH3-N volatilization and NO3-N transfer through leaching and surface runoff, in comparison to the use of urea (LORENSINI et al 2012). In addition to lower transfers, the lower mineralization rate probably improves the synchronism between N release and its uptake by the grapevines (MELO et al 2012, LORENSINI et al 2014.…”

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

“…Nitrogen availability depends on the content of the directly available N represented by inorganic N forms as well as organic and mineralizable forms during its cycle (Camargo et al, 1997;Lorensini et al, 2014). Approximately 98 % of total soil N occurs in organic forms, and a significant portion of N is not readily available to plants (Urquiaga and Zapata, 2000).…”