01847nam a2200241 a 450000100080000000500110000800800410001910000200006024500680008026000360014830000100018452012230019465000150141765000100143265000100144265000160145265000270146865300190149565300340151470000200154870000200156870000170158811332772024-04-10       1982    bl uuuu     u0uu1 u    #d1 aSILVA, D. A. da  aIrrigation by porous capsule method under hidrostatic pressure.  aPetrolina: EMBRAPA-CPATSAc1982  a26 p.  aA field experiment was contucted at an Experiment Station of EMBRAPA in Pernambuco, Brazil with the objectives to evaluate the technical feasibility of irrigation by porous capsule under hydrostatic presure and to determine the effect of plant population on corn production. The experiment tested hydrostatic pressures of 0.35, 0.50 and 0.70 m and corn populations of 1, 4, 7, 10 and 13 plants/capsule with three replicates in a randomized block design. Each replicate consisted of 10 capsules installed at 0.25 m deep along the contour lines with absolutely no slope. The hydrostatic pressure significantly influenced water release from the capsule. Total water consumption varied from 7.96 to 10 cm/ha thereby indicating the extent of water saving. The hydrostatic pressure did no affect production significantly but the differences due to plant population were significant at 0.01 leyel. A second degree quadratic equation described satisfactorily the yield curve and estimated that 9 plants/capsule would give the best grain production. In the present wtudy 7 plantas/capsule gave the highest production with a water use efficiency of 2.0 kg/m3, which compared to conventional methods of irrigation is rather high.  airrigation  awater  aÁgua  aIrrigação  aPressão Hidrostática  aCapsula porosa  aIrrigação não convencional1 aCARVALLO, H. O.1 aSILVA, A. de S.1 aGHEYI, H. R.