Quantification of the relationship between root parameters and soil macropore parameters under different land use systems in Retisol

The study aimed to quantify the relationship between root parameters and soil macropore characteristics in two soil layers of Retisol from a hilly landscape in Western Lithuania, as influenced by different land use systems. The decreases in root volume and root length density were dependent on land use and soil depth. The values of root length density and root volume at 0-20 cm depth tended to decrease in the following order: grassland > forest > arable land under conventional tillage. The highest volume in the framework of macropores was recorded for medium-size pores under arable land (3.02%), for fine pores (2.56%) in forest soil and very fine pores in grassland soil (below 1.19%) at the 0-10 cm soil depth, while at 10-20 cm soil depth, the coarse macropores dominated in the arable land system (below 1.41%). Root length density, root volume and the volume of very fine macropores had close relationships (p < 0.01, r = 0.91 and r = 0.68, respectively) under different land use at 0-20 cm depth. In Retisol, the roots were concentrated at 0-10 cm soil depth, and their volume was higher compared to the 10-20 cm depth. Plant roots increased the volume of very fine macropores in all land use systems, within the entire 0-20 cm soil depth

Permeabilidade ao ar em Latossolo Vermelho sob diferentes sistemas de manejo

A permeabilidade ao ar pode ser utilizada para avaliar alterações que ocorrem na estrutura do solo em virtude da adoção de diferentes sistemas de manejo. Este estudo testou a hipótese de que o menor revolvimento do solo sob sistema plantio direto resulta na formação de poros mais contínuos e melhor condição de aeração no solo. O objetivo deste trabalho foi avaliar, por meio da permeabilidade ao ar (Ka), da porosidade de aeração (εa) e dos índices de continuidade de poros (K1 e N), a aeração em um Latossolo Vermelho distrófico sob preparo convencional (PC) e sistema plantio direto (SPD). Oitenta amostras de solo (2 tratamentos x 2 profundidades x 20 repetições) com estrutura indeformada foram coletadas de cada sistema de manejo do solo nas profundidades de 0-0,10 e 0,10-0,20 m em área experimental do Instituto Agronômico do Paraná, no município de Ponta Grossa, Paraná. Depois de saturadas e equilibradas em seis potenciais mátricos (-2, -6, -10, -30, -70 e -100 kPa), determinou-se a permeabilidade ao ar e a porosidade de aeração em cada potencial. Também foram determinados a densidade do solo, a densidade de partícula, o carbono orgânico e a porosidade. A densidade do solo não consistiu em fator limitante, ficando abaixo do limite crítico para solos argilosos nos dois sistemas. No SPD, o maior volume de microporos resultou em maior retenção de água no intervalo de umidade avaliado (-2 a -100 kPa) e em maior volume de poros bloqueados para o fluxo de ar (εb), ou seja, redução de Ka. Na profundidade avaliada (00,20 m), os índices de continuidade de poros (K1 e N) revelaram que o PC apresentou poros mais contínuos do que o SPD, contradizendo a hipótese testada

Impact of Tillage Methods on Environment, Energy and Economy

ISSN 2210-4410, eISBN 9783319990767Soil tillage involves the mechanical manipulation of soils used for crop production. Tillage is done to prepare an optimal seedbed, to loosen compacted soil layers, to control weeds, to increase aeration, to incorporate plant residues into the soil, to facilitate water infiltration and soil moisture storage, and to control soil temperature. Nonetheless, soil tillage is one of the highest energy-consuming, environment-polluting and expensive technological processes in agriculture. Conventional tillage with ploughing is the most widely used practice. Conventional tillage has low efficiency, requires high-powered tractors with high fuel consumption and greenhouse gases emissions. Moreover, the cost of conventional tillage is high, and the influence on the soil structure, degradation, leaching of nutrients and the most fertile soil is negative. Here we review the impact of tillage methods on soil quality, environment and economy. Due to the disadvantages of conventional tillage, sustainable tillage area increases each year by 4-6 million ha worldwide. Under sustainable tillage such as minimal or no-tillage, the total soil surface modified by the wheels of agricultural machinery is 20-40% lower than for conventional tillage. Sustainable tillage preserves better soil physical properties and biological processes. A comparison of tillage methods show that no-tillage has the highest energy efficiency ratio of 14.0, versus 12.4 for deep ploughing. The most expensive tillage operation is deep ploughing. The use of agricultural machinery under sustainable tillage conditions and preparation of soils without using a plough can reduce costs from 25% to 41%, compared with conventional tillageVytauto Didžiojo universitetasŽemės ūkio akademij