Balanço hídrico de um solo podzolizado de Lins e Marília cultivado com cafeeiros

Abstract

Termos de indexação: cafeeiro, solo podzolizado, evapotranspiração, drenagem profunda, armazenamento de umidade.

Soil profile internal drainage for a central pivot fertigated coffee crop

“…As expected an excellent regression was found for cumulative values of Q and P (Figure 3). The Q component, responsible for ground water recharge, is considered negligible in several WB studies, but can reach values of the order of ET r (Pereira, 1986). discuss the fact that Q below root zone (1.0 m) estimated through Darcy's equation is a very difficult task mainly due to soil spatial variability.…”

Comparison between climatological and field water balances for a coffee crop

“…Reference evapotranspiration ETo was estimated through the Penman-Monteith method FAO -1998 cited by Pereira et al (2002) and the maximum evapotranspiration of the crop was obtained through the use of a crop coefficient estimated in the same experiment. Rainfall and irrigation were measured with "Ville de Paris" raingages; soil water storage was calculated through the trapezoidal method, for the 1 m soil layer (L = 1 m), using neutron probe soil moisture valuations; runoff was measured on 12 m 2 framed sub-plots, colleting the surface water flow by gravity in 200 L tanks located down slope; and the soil water fluxes at the lower boundary were calculated through the Darcy-Buckingham approach using a K (θ) relation obtained in the same field (Silva et al, 2007) and hydraulic gradients measured through tensiometers installed in the soil profile.…”

“…This contabilization can be made through direct measurements of all components in the field (Reichardt & Timm, 2004), or estimated from climatological data through the use of specific programs (Pereira et al, 2002).…”

“…A crop coefficient (Kc) is used to trans-form the grass ETo into the crop potential evapotranspiration (ETc), which is a function of the phenological phases of the crop, crop species and variety, plant architecture and leaf area. Pereira (1986) used with success the climatologic water balance to study maximum and minimum soil water storages for a podzolic soil of the São Paulo State, in Brazil. Souza et al (2002) made an analysis of the climatologic water balance simulation for the coffee crop, irrigated under different management conditions in Lavras, MG, Brazil.…”

Estresse hídrico e características agronômicas de materiais superprecoces de milho (>i<Zea mays>/I< L.)

“…Além disso, no sistema de semeadura direta (Muzilli, 1985) Dentre os principais efeitos tem-se: redução na fotossíntese e no crescimento (Kramer, 1974)~ o crescimento radicular é geralmente favorecido comparado ao crescimento total que é reduzido (Davidson, 1969;Hoffinan et al, 1971;Lancher, 1975;Begg & Tumer, 1976); redução na transpiração das plantas (Crafts, 1968;Hsiao & Acevedo, 1974;Sutcliffe, 1980); redução inicial na respiração, seguida de um aumento transitório e, finalmente, de uma diminuição ao aumentar o período da deficiência hídrica; redução da translocação de compostos orgânicos, como tem sido relatado por Roberts (1964) (Reichardt, 1985). A metodologia do balanço hídrico num volume de controle de solo nas modalidades sequencial e cíclico, tem sido largamente utilizada em pesquisas de uso consuntivo de água, entre outros destaca-se: Rose & Stern (1967); Pereira (1986); Reichardt (1974); Castro (1979) e Oliveira (1991) (Jensen, 1974).…”