3303 results

Agronomic effectiveness of fluid and solid phosphate fertilizers

W.B. Scivittaro, A.E. Boaretto, T. Muraoka

01/Sep/1997

The effectiveness of fluid (phosphoric acid and 10-30-00 colloidal suspension) and solid (monoammonium phosphate and triple superphosphate) fertilizers was evaluated in a greenhouse experiment at the Center for Nuclear Energy in Agriculture (CENA), University of São Paulo, Piracicaba, State of São Paulo, Brazil, from June to October, 1992. Corn plants were grown in pots (8 plants per pot; 3 replicates) containing 1 kg of two red-yellow latosols with different phosphorus retention capacities, for three successive cycles (30 days each). The […]

Carbon and nitrogen microbial biomass of soils under different forest types

E.F. da Gama-Rodrigues, A.C. da Gama-Rodrigues, N.F. de Barros

01/Sep/1997

The fumigation-extraction method was used for measuring soil microbial biomass of C (BM-C) and N (BM-N) in a red-yellow latosol under different forest types. Soil samples from eucalypt and pine plantations presented higher values of BM-C (223.72 and 207.39 mg kg-1 of C in the soil, respectively) than samples from Piptadenia rigida and regenerating secondary forest (82.94 and 79.47 mg kg-1 of C in the soil, respectively). Similar results were obtained for the litter layer. On the other hand, the […]

Rainfall erosivity indices, soil losses and erodibility factor for two soils from the cerrado region – first approximation

J.J.G.S.M. Marques, R.C. Alvarenga, N. Curi, D.P. Santana, M.L.N. Silva

01/Sep/1997

The objectives of this paper were: to verify the adequacy of different rainfall erosivity indices, to compare two equations to calculate the rainfall kinetic energy and to estimate the USLE K-factor (soil erodibility) of two soils (Dark – Red Latosol and Red – Yellow Podzolic soil) from the Sete Lagoas (MG) region. There was not a significant difference between the studied equations to calculate rainfall kinetic energy. The EI30 index showed to be a good rainfall erosivity predictor and can […]

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