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Balota E.L.,IAPAR Agronomic Institute of Parana State | Machineski O.,IAPAR Agronomic Institute of Parana State | Honda C.,IAPAR Agronomic Institute of Parana State | Yada I.F.U.,IAPAR Agronomic Institute of Parana State | And 3 more authors.
Land Degradation and Development | Year: 2016

Swine slurry is a common agricultural fertilizer in many countries. However, its long-term use in large amounts can cause excess nutrient accumulation, alter soil compounds, and potentially influence critical microbial populations such as arbuscular mycorrhizal fungi, which have important roles in plant nutrition and soil sustainability. This work determined if arbuscular mycorrhizal status, external mycelium, and glomalin-related soil protein content were affected by long-term swine slurry application to different soil tillage systems. The experiment was conducted on a clayey oxisol, in southern Brazil. Swine slurry (0, 30, 60, 90, and 120m3ha-1y-1) was applied for 15years to conventional tillage and no tillage soil prior to the summer (soybean or maize) and winter (wheat or oats) crop seasons. Swine slurry decreased mycorrhizal root colonization, spore number, and total external mycelium. Swine slurry increased active external mycelium and both easily extractable and total glomalin-related soil protein. No-tillage soil had more glomalin-related soil protein than conventional tillage soil. The most significant response variables were root colonization, easily extractable glomalin-related soil protein, and total external arbuscular mycorrhizal mycelia. Long-term application of swine slurry in this environment, even at high rates, did not adversely affect crop yield but did influence arbuscular mycorrhizae fungi and their products in the soil environment. Benefits of swine slurry application for crop nutrition must be weighed against potential adverse consequences for the size, activity, and benefits of the mycorrhizal community to subsequent annual crops. © 2016 John Wiley & Sons, Ltd.


Balota E.L.,IAPAR Agronomic Institute of Parana State | Machineski O.,IAPAR Agronomic Institute of Parana State | Hamid K.I.A.,IAPAR Agronomic Institute of Parana State | Yada I.F.U.,IAPAR Agronomic Institute of Parana State | And 3 more authors.
Science of the Total Environment | Year: 2014

Swine waste can be used as an agricultural fertilizer, but large amounts may accumulate excess nutrients in soil or contaminate the surrounding environment. This study evaluated long-term soil amendment (15years) with different levels of swine slurry to conventional (plow) tillage (CT) and no tillage (NT) soils. Long-term swine slurry application did not affect soil organic carbon. Some chemical properties, such as calcium, base saturation, and aluminum saturation were significantly different within and between tillages for various application rates. Available P and microbial parameters were significantly affected by slurry addition. Depending on tillage, soil microbial biomass and enzyme activity increased up to 120m3ha-1year-1 in all application rates. The NT system had higher microbial biomass and activity than CT at all application levels. There was an inverse relationship between the metabolic quotient (qCO2) and MBC, and the qCO2 was 53% lower in NT than CT. Swine slurry increased overall acid phosphatase activity, but the phosphatase produced per unit of microbial biomass decreased. A comparison of data obtained in the 3rd and 15th years of swine slurry application indicated that despite slurry application the CT system degraded with time while the NT system had improved values of soil quality indicators. For these Brazilian oxisols, swine slurry amendment was insufficient to maintain soil quality parameters in annual crop production without additional changes in tillage management. © 2014 Elsevier B.V.


Balota E.L.,IAPAR Agronomic Institute of Parana State | Calegari A.,IAPAR Agronomic Institute of Parana State | Nakatani A.S.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Coyne M.S.,University of Kentucky
Agriculture, Ecosystems and Environment | Year: 2014

Soil degradation in Brazil is a concern due to intensive agricultural production. Combining conservation practice, such as no-tillage, with winter cover crops may increase microbial activity and enhance soil quality more than either practice alone. This research evaluated the benefits of long-term (23 years) winter cover crops and reduced tillage on soil microbial quality indicators in an Oxisol from Paraná State, Southern Brazil. The winter cover treatments were: fallow, black oat, wheat, radish, blue lupin, and hairy vetch in conventional (plow) or no-tillage management; the summer crop was a soybean/maize rotation. Soil quality parameters included organic C, microbial biomass C and N, total and labile polysaccharide, easily extractable and total glomalin-related soil protein, and enzyme activity. Winter crops increased soil microbial quality parameters compared to fallow in both tillage systems, with greater relative increase in conventional than no-tillage. No-tillage had higher microbial biomass, polysaccharide, glomalin-related soil protein, and soil enzyme activity than conventional tillage. Including legumes in the crop rotation was important for N balance in the soil-plant system, increasing soil organic C content, and enhancing soil quality parameters to a greater extent than grasses or radish. The microbial parameters proved to be more sensitive indicators of soil change than soil organic C. Cultivating winter cover crop with either tillage is a beneficial practice enhancing soil microbial quality and also soil organic C stocks. © 2014.

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