Resumen en: The aim of this study was a survey of the estimated costs of soil erosion, an issue of fundamental importance in view of the current worldwide discussion...

http://www.redalyc.org/pdf/1802/Resumenes/Abstract_180218547001_2.pdf

Revista Brasileira de Ciência do Solo

Silicon improves seed germination and alleviates oxidative stress of bud seedlings in tomato under water deficit stress.

Soil compaction management and soybean yields with cover crops under no-till and occasional chiseling

Agriculture and livestock integration is a sustainable practice that improves both crop yield and pasture recuperation/formation. However, to achieve success it is important to identify crop cultivars more adapted to intercropping with grasses. Th erefore, the objective was to evaluate nutrient concentration and grain yield of soybean (Glycine max (L.) Merr.) cultivars with diff erent life cycles as aff ected by palisadegrass (Brachiaria brizantha (Hochst. ex A. Rich) Stapf) intercropped in the same furrow at diff erent depths, in a no-till system, as well as dry matter production and protein concentration of palisadegrass pasture. Experiments were performed during two growing seasons, on a Typic Haplorthox, at Botucatu, Sao Paulo State, Brazil. Th e experimental design was a randomized block, arranged in a 2 × 4 factorial scheme, with six replications. Treatments consisted of two cropping systems (sole cropped soybean; soybean and palisadegrass intercropped) and four soybean cultivars (super-early cycle (Monsoy 6101), early cycle (Embrapa 48), normal cycle (BRS 133), and late cycle (Emgopa 313)). Life cycle duration of the soybean had a marked eff ect, and only early cycle soybean were successful intercrops. Intercropping palisadegrass with super-early or early soybean cultivars were viable options to crop-livestock integration, because they did not aff ect both soybean or palisadegrass yield. In addition, with these cultivars, it was possible to cultivate grain and then aft erward more time for cattle (Bos taurus and Bos indicus) grazing in the same area, providing greater revenue compared to sole soybean cropped or in the intercropping with longer cycle cultivars.

An Innovative Crop–Forage Intercrop System: Early Cycle Soybean Cultivars and Palisadegrass

Swine manure is a good nutrient source, but may have a negative impact on the environment when inadequately used. The aim of this work was to evaluate changes in properties of soils under no-till grain production and long-term swine manure fertilization. Soil samples from three representative soils types (Oxisol, Inceptisol and Leptosol) from Western Santa Catarina, Southern Brazil, were collected under no-tillage cultivation and surface application of swine manure for about 15 years and over 20 years. Samples from areas treated with mineral fertilizer and unfertilized controls (under forest vegetation) were also collected from seven soil layers (0-5, 5-10, 10-20, 20-30, 40-50, 70-80, and 100-110 cm) to evaluate soil organic matter content and available P, K, Cu, and Zn. Long-term swine manure application caused nutrient accumulation (P, K, Cu and Zn) in the top soil layer, mainly in the top 5 cm of soil. Soil organic matter was not affected by manure application. In general, the annual manure applications did not affect the chemical properties of the subsoil. In Leptosol and Inceptisol, however, increased P concentrations were found in the 40-50 cm and 70-80 cm soil layers, indicating a greater potential for P loss in these soils. Exchangeable Zn and Cu was accumulated mainly in the top 10 cm of the Oxisol and in the top 20 cm of the Inceptisol and Leptosol. The accumulation of nutrients in the top soil layer (0-5 cm) indicated a greater potential for nutrient loss than in soils treated with conventional mineral fertilizer.

/pdf/atributos-quimicos-do-solo-influenciados-por-sucessivas-1llpp09a3z.pdf

Atributos químicos do solo influenciados por sucessivas aplicações de dejetos suínos em áreas agrícolas de Santa Catarina

O manejo correto da adubacao potassica pode minimizar perdas assim como evitar o esgotamento de K do solo. Objetivou-se estudar a dinâmica do K no perfil do solo em funcao do teor de argila e do teor do nutriente resultantes da adubacao da soja. Foram coletados solos de texturas media e argilosa, que vinham sendo adubados com 0, 60, 120, e 180 kg ha-1 de K2O na soja por 6 anos. O experimento foi conduzido em casa de vegetacao, em tubos de PVC estratificados nas profundidades de 0-5, 5-10, 10-20, e 20-40 cm. Na superficie das colunas, aplicaram-se mais 80 kg ha-1 de K2O. Durante 16 semanas, foi aplicada, semanalmente, agua em quantidade equivalente a 100 mm de chuva. Em cada aplicacao, o volume de solucao percolada foi determinado, assim como as quantidades de K contidas nessa solucao. Apos a desmontagem das colunas de solo, foram determinados os teores de K trocavel e nao-trocavel nas diferentes profundidades. A percolacao de K foi maior no solo de textura argilosa, que tinha mais K disponivel devido ao maior efeito residual da adubacao potassica anterior. A intensidade de lixiviacao foi proporcional ao teor de K disponivel, mas inicialmente a lixiviacao foi mais intensa no solo mais arenoso, decrescendo com o tempo. No argiloso, as perdas foram mais constantes. Houve proporcionalidade entre teor inicial e lixiviacao no perfil do solo, nas duas formas de K e nos dois tipos de solo. Conclui-se que o efeito residual da adubacao potassica aumentou as quantidades de K percolado. A movimentacao de K no perfil do solo teve boa relacao com o teor inicial de K no solo, resultante da adubacao potassica anterior nos dois tipos de solo. A passagem de K considerado nao-trocavel para trocavel foi rapida e influenciou na lixiviacao.

/pdf/lixiviacao-de-potassio-em-funcao-da-textura-e-da-91ai01hg4q.pdf

Lixiviação de potássio em função da textura e da disponibilidade do nutriente no solo

Potassium cycling in a corn-brachiaria cropping system

Potassium (K) leaching is affected by soil texture and available K, among other factors. In this experiment, effects of soil texture and K availability on K distribution were studied in the presence of roots, with no excess water. Soils from two 6-year field experiments on a sandy clay loam and a clay soil fertilized yearly with 0, 60, 120, and 180 kg ha−1 of K2O were accommodated in pots that received 90 kg ha−1 of K2O. Soybean was grown up to its full bloom (R2). Under field conditions, K leaching below the arable layer increased with K rates, but the effect was less noticeable in the clay soil. Potassium leaching in a sandy clay loam soil was related to soil K contents from prior fertilizations. With no excess water, in the presence of soybean roots, K distribution in the profile was significant in the lighter textured soil but was not apparent on the heavier textured soil.

Potassium Leaching as Affected by Soil Texture and Residual Fertilization in Tropical Soils

Soil Sci. Soc. Am. J. 77:1724–1731 doi:10.2136/sssaj2012.0310 Received 21 Sept. 2012. * Corresponding author (rosolem@fca.unesp.br). © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. Soil Organic Matter and Physical Attributes Affected by Crop Rotation Under No-till Soil & Water Management & Conservation

Soil Organic Matter and Physical Attributes Affected by Crop Rotation Under No-till

O objetivo deste trabalho foi avaliar a influencia dos cultivos de outono-inverno e primavera, em sistema de plantio direto, nos agregados e materia orgânica de um Latossolo. O experimento foi conduzido durante as safras 2006/2007, 2007/2008 e 2008/2009. No outono-inverno foram estabelecidas parcelas principais com braquiaria (Urochloa ruziziensis), sorgo granifero (Sorghum bicolor) e sorgo consorciado com braquiaria. Na primavera, foram cultivados, em subparcelas, milheto (Pennisetum glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense), crotalaria (Crotalaria juncea) ou pousio. A soja foi cultivada como safra de verao, o que totalizou 12 tratamentos. A massa de materia seca e o crescimento radicular das plantas de cobertura da primavera foram determinados em 2006 e 2008. Foram coletadas amostras de solo nas camadas de 0-5 e 5-10 cm, apos o manejo das plantas de cobertura de primavera, no primeiro e terceiro anos agricolas. Foram determinados o diâmetro medio ponderado, o diâmetro medio geometrico, o indice de estabilidade de agregados, os agregados maiores que 2 mm, a materia orgânica e os teores de carbono orgânico total nas amostras coletadas no terceiro ano. O milheto e 'Cober Crop' produziram maior quantidade de massa de materia seca e maior crescimento radicular. A estruturacao do solo melhorou com a rotacao dos cultivos das plantas de cobertura antecedentes a safra de verao. O cultivo de 'Cober Crop' e milheto influenciou a formacao de macroagregados nas camadas superficiais

http://www.scielo.br/pdf/pab/v45n12/v45n12a21.pdf

Rodrigo Arroyo Garcia

Papers

Lixiviação de potássio em função da textura e da disponibilidade do nutriente no solo

Potassium cycling in a corn-brachiaria cropping system

Potassium Leaching as Affected by Soil Texture and Residual Fertilization in Tropical Soils

Soil Organic Matter and Physical Attributes Affected by Crop Rotation Under No-till

Agregados em um Latossolo sob sistema plantio direto e rotação de culturas