Runoff in Oxisol under different agroecosystems in the northeast part of Pará State [Escoamento superficial em Latossolo Amarelo distrófico típico sob diferentes agroecossistemas no nordeste paraense]
da Costa C.F.G.,Embrapa Amazonia Oriental |
Figueiredo R.O.,Embrapa Meio Ambiente |
Oliveira F.A.,UFRA |
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013
In the watershed of the Timboteua and Buiuna streams in the State of Pará, the effect of land use change and soil management on the runoff rates was evaluated. Eighteen experimental plots (1 m2) were established, three in each one of the six evaluated agroecosystems as follows: i) 20 years Secondary vegetation ("Capoeira") (CP), ii) Agroforestry system / slash-and-burn (SQ), iii) Agroforestry system / chop-and-mulch (ST), iv) Cassava crop / chop-and-mulch (RT), v) Cassava crop / slash-and-burn (RQ), vi) Cattle pasture / slash-and-burn (PQ). Nearby these plots two rain gauges and three rainwater collectors for monitoring of precipitation were also installed. Along 2010 rainy season 234 samples were collected on 26 different dates. A strong correlation was found between precipitation and runoff, being the highest value of 54.53% of total volume of superficial flow for Cattle pasture degraded and lowest of 1.11% for Agroforestry system that was under recovery for 7 years after burning. The runoff decreased in agroecosystems with lower percentage of organic material in relation to systems with higher percentage.
da Silva R.T.L.,Federal University of Santa Maria |
Andrade D.P.,Federal Rural University of Pernambuco |
Melo E.C.,Campus de Capitao Poco |
Palheta E.C.V.,Federal University of Para |
Revista Caatinga | Year: 2011
The cowpea is a leguminous of great importance for human consumption, providing a source of protein for most of urban population of northern Brazil, therefore the aim of this paper was to evaluate the efficiency of strains of Bradyrhizobium out in association with phosphate and potassium fertilization (PK) in cowpea at the field level in the municipality of Capitão Poço - PA. Two experiments were carried out in randomized blocks with four replications, consisting of five treatments, being two strains of Bradyrhizobium - BR 3262 and BR 3267, a treatment only with PK, another one with NPK in the formulation (10-28-20) and a control. It was evaluated the grain yield, the number of pods and weight of 100 seeds. Fertilization with phosphorus and potassium represented a significant increase in the yield of cowpea, however inoculation with both strains did not increase production.
Silva J.A.R.D.,Federal Rural University of Amazonia |
Araujo A.A.D.,State University of Ceara |
Junior J.D.B.L.,Para State University |
Santos N.D.F.A.D.,UFRA |
And 2 more authors.
Pesquisa Agropecuaria Brasileira | Year: 2011
The objective of this work was to evaluate the effects of a silvipasture system on the thermal comfort of 20 female buffaloes, from which 10 raised in under nonshaded paddocks (SS) and 10 in paddocks shaded by Racosperma mangium (CS), in Belém county, PA, Brazil. All animals were fed in pastures with Urochloa humidicola, and had free access to drinking water and mineral salt. Every three days, measurements were made for air temperature (TA), relative humidity (UR), black globe temperature (TGN), rectal temperature (TR), respiratory rate (FR), heart rate (FC), and body surface temperature (TSC), in the morning (7 AM) and in the afternoon (1 PM). The values of TR, TSC, RR and FR, mainly for the SS group, were higher in the afternoon. The TR, TSC and FR showed a significant and positive correlation with TA and the temperature and humidity index (ITGU), and a negative correlation with UR. These correlations were higher for the less rainy period. The FR showed significant and positive correlations with TA and ITGU, during both the most and the less rainy seasons, and negative correlations with UR only in the rainy season. The forestation of pasture areas is efficient to increase the thermal comfort for Murrah females, especially in the afternoon.
Zerbato C.,Sao Paulo State University |
Furlani C.E.A.,Sao Paulo State University |
de Almeida R.F.,Sao Paulo State University |
Voltarelli M.A.,Sao Paulo State University |
Engenharia Agricola | Year: 2015
Peanut crop (Arachis hypogaea L.) mechanization has been improved over the years; however there are drawbacks that affect the quality of operations. Thus, this article's objectives were to evaluate the operational performance of the mechanized sowing of peanut crop according to seeding densities (10, 14, and 18 seeds m-1) and seed sizes (21 and 23 mm). It was observed that the seeds of 23 mm had shorter average number of days to emergence and a higher percentage of emergences, occurring the opposite to the seeding density of 18 seeds m-1. The higher the seeding density, the largest was the plant stand, whereas the 23 mm seed obtained the best results and the same with the seeding density of 14 seeds m-1 that had a higher percentage of normal spacing. The densities of 14 and 18 seeds m-1 reflected in higher yields, being always superior to the 23 mm seeds.
Viegas I.J.M.,UFRA |
Rodrigues Galvao J.,Instituo de Ciencias Agrarias UFRA |
Da Silva Jr. M.L.,Instituo de Ciencias Agrarias UFRA |
Carvalho Melo N.,Sao Paulo State University |
De Oliveira M.S.,Secretaria de Meio Ambiente SEMA
Revista Caatinga | Year: 2014
The objective was to evaluate the effect of the omission of macronutrient and micronutrient boron in dry matter production, the characterization of the symptoms of nutritional deficiencies and mineral composition in plants of ipeca, an experiment was conducted in greenhouse conditions by the technique the missing element and visual diagnosis. A randomized block experimental design with four repetitions and the treatments were: complete and omissions of N, P, K, Ca, Mg, S and B. The analytical results demonstrated that the production of dry matter was affected in all of the treatments with omission of nutrients and that the ipeca plants presented characteristic symptoms of nutritional deficiencies due to the omissions of N, P, K, Ca, Mg, S and B and the concentrations of the macronutrients and of the micronutrient boron in the different parts of the ipeca plant varied when a certain nutrient was omitted in the solution.