Soil carbon and nitrogen mineralization caused by pig slurry application under different soil tillage systems

The objective of this work was to evaluate the change in soil C and N mineralization due to successive pig slurry application under conventional tillage (CT) and no tillage (NT) systems. The experiment was carried out in a clayey Latossolo Vermelho eutrófico (Rhodic Eutrudox) in Palotina, PR, Brazil. Increasing doses of pig slurry (0, 30, 60 and 120 m³ ha-1 per year) were applied in both tillage systems, with three replicates. Half of the pig slurry was applied before summer soil preparation, and the other half before the winter crop season. The areas were cultivated with soybean (Glycine max L.) and maize (Zea mays L.) in the summers of 1998 and 1999, respectively, and with wheat (Triticum sativum Lam.) in the winters of both years. Soil samples were collected at 0-5, 5-10, and 10-20 cm depths. Under both CT and NT systems, pig slurry application increased C and N mineralization. However, increasing pig slurry additions decreased the C to N mineralization ratio. Under the NT system, C and N mineralization was greater than in CT system.

Regeneration process from seed crop to saplings : a case study in uneven-aged Norway spruce-dominated stands in southern Finland

Abstract

Subunit composition of seed storage proteins in high-protein soybean genotypes

The objective of this work was to quantify the accumulation of the major seed storage protein subunits, β-conglycinin and glycinin, and how they influence yield and protein and oil contents in high-protein soybean genotypes. The relative accumulation of subunits was calculated by scanning SDS-PAGE gels using densitometry. The protein content of the tested genotypes was higher than control cultivar in the same maturity group. Several genotypes with improved protein content and with unchanged yield or oil content were developed as a result of new breeding initiatives. This research confirmed that high-protein cultivars accumulate higher amounts of glycinin and β-conglycinin. Genotypes KO5427, KO5428, and KO5429, which accumulated lower quantities of all subunits of glycinin and β-conglycinin, were the only exceptions. Attention should be given to genotypes KO5314 and KO5317, which accumulated significantly higher amounts of both subunits of glycinin, and to genotypes KO5425, KO5319, KO539 and KO536, which accumulated significantly higher amounts of β-conglycinin subunits. These findings suggest that some of the tested genotypes could be beneficial in different breeding programs aimed at the production of agronomically viable plants, yielding high-protein seed with specific composition of storage proteins for specific food applications.

Analysis of sensitivity with respect to a compositional parameter : A comment on 'Local sensitivity analysis for compositional data with application to soil texture in hydrologic modelling' by L. Loosvelt and co-authors

A comment about the article “Local sensitivity analysis for compositional data with application to soil texture in hydrologic modelling” writen by L. Loosvelt and co-authors. The present comment is centered in three specific points. The first one is related to the fact that the authors avoid the use of ilr-coordinates. The second one refers to some generalization of sensitivity analysis when input parameters are compositional. The third tries to show that the role of the Dirichlet distribution in the sensitivity analysis is irrelevant

Leaf mineral composition of grafted eggplant grown in soil infested with Verticillium and root-knot nematodes

The objective of this work was to determine differences in leaf mineral composition between ungrafted and grafted onto (Solanum torvum) eggplant (Solanum melongena), cultivars 'Faselis' and 'Pala', grown in a soil infested with Verticillium dahliae and Meloidogyne incognita, or in a noninfested soil. Grafting increased leaf P and Mn concentrations, and decreased N concentrations, in both soils. Grafting also enhanced leaf Ca concentration of 'Pala', but it did not affect that of 'Faselis' depending on the cropping year. Leaf Mg concentration of grafted plants in infested soil was lower than that of ungrafted ones in noninfested soil. Results showed that, under the same fertilization program, the grafted 'Faselis' plants used the nutrients more efficiently than the 'Pala' ones. Use of S. torvum as a rootstock for 'Faselis' resulted in an effective protection against multiple pathogen infestation. Fertilization may be necessary when grafted 'Faselis' plants are grown in a soil infested with the pathogens, since grafting and infestation generally decrease leaf N, Mg, Ca and Fe concentrations, either by reducing the nutrient concentrations directly or by increasing leaf Mn concentration.