Titre de série :	Samaru Miscellaneous Paper, 44
Titre :	Construction and prformance of a hydraulic weighing lysimeter at Samaru, Nigeria
Type de document :	texte imprimé
Auteurs :	Kowal, J. ; Stoskinger, K. R.
Mention d'édition :	Institute for Agricultural Research, Samaru/ahmadu Bello University
Editeur :	Institute for Agricultural Research, Samaru/Ahmadu Bello University
Année de publication :	1973
ISBN/ISSN/EAN :	CI-04511
Note générale :	A critical factor affecting crop production in the savana zone of west Africa is the availability of water to crops. To estimate the amount of water available for crops it is necessary to know the amount of supply by rainfall or irrigation, the amount used in evapotranspiration can be estimated by measuring changes in soil moisture by direct sampling, with tensiometers or a neutron probe or by calculation from meteorological data using formulae such as that of Penman (1948) or thornthwaite (1954). Penman's method only estimates the evaporation from a free water surface and Thornthwaite's formula is not very accusate for short periods. This paper describes the construction and performance of an hydraulic weighing bysineter that has been used successfully at Samaru since 1968.
Langues :	Anglais (eng)
Mots-clés :	Hydrologie  Pluviométrie  Production agricole  Evaporation  Evapotranspiration  Mesure et observation  Limnimétrie  Méthode de Penman
Index. décimale :	551.48 Hydrologie :
Résumé :	A critical factor affecting crop production in the savana zone of west Africa is the availability of water to crops. To estimate the amount of water available for crops it is necessary to know the amount of supply by rainfall or irrigation, the amount used in evapotranspiration can be estimated by measuring changes in soil moisture by direct sampling, with tensiometers or a neutron probe or by calculation from meteorological data using formulae such as that of Penman (1948) or thornthwaite (1954). Penman's method only estimates the evaporation from a free water surface and Thornthwaite's formula is not very accusate for short periods. This paper describes the construction and performance of an hydraulic weighing bysineter that has been used successfully at Samaru since 1968.
Note de contenu :	A critical factor affecting crop production in the savana zone of west Africa is the availability of water to crops. To estimate the amount of water available for crops it is necessary to know the amount of supply by rainfall or irrigation, the amount used in evapotranspiration can be estimated by measuring changes in soil moisture by direct sampling, with tensiometers or a neutron probe or by calculation from meteorological data using formulae such as that of Penman (1948) or thornthwaite (1954). Penman's method only estimates the evaporation from a free water surface and Thornthwaite's formula is not very accusate for short periods. This paper describes the construction and performance of an hydraulic weighing bysineter that has been used successfully at Samaru since 1968.

Samaru Miscellaneous Paper, 44. Construction and prformance of a hydraulic weighing lysimeter at Samaru, Nigeria [texte imprimé] / Kowal, J. ; Stoskinger, K. R.  . -  Institute for Agricultural Research, Samaru/ahmadu Bello University . - Institute for Agricultural Research, Samaru/Ahmadu Bello University, 1973.
ISSN : CI-04511
A critical factor affecting crop production in the savana zone of west Africa is the availability of water to crops. To estimate the amount of water available for crops it is necessary to know the amount of supply by rainfall or irrigation, the amount used in evapotranspiration can be estimated by measuring changes in soil moisture by direct sampling, with tensiometers or a neutron probe or by calculation from meteorological data using formulae such as that of Penman (1948) or thornthwaite (1954). Penman's method only estimates the evaporation from a free water surface and Thornthwaite's formula is not very accusate for short periods. This paper describes the construction and performance of an hydraulic weighing bysineter that has been used successfully at Samaru since 1968.
Langues : Anglais (eng)

Mots-clés :	Hydrologie  Pluviométrie  Production agricole  Evaporation  Evapotranspiration  Mesure et observation  Limnimétrie  Méthode de Penman
Index. décimale :	551.48 Hydrologie :
Résumé :	A critical factor affecting crop production in the savana zone of west Africa is the availability of water to crops. To estimate the amount of water available for crops it is necessary to know the amount of supply by rainfall or irrigation, the amount used in evapotranspiration can be estimated by measuring changes in soil moisture by direct sampling, with tensiometers or a neutron probe or by calculation from meteorological data using formulae such as that of Penman (1948) or thornthwaite (1954). Penman's method only estimates the evaporation from a free water surface and Thornthwaite's formula is not very accusate for short periods. This paper describes the construction and performance of an hydraulic weighing bysineter that has been used successfully at Samaru since 1968.
Note de contenu :	A critical factor affecting crop production in the savana zone of west Africa is the availability of water to crops. To estimate the amount of water available for crops it is necessary to know the amount of supply by rainfall or irrigation, the amount used in evapotranspiration can be estimated by measuring changes in soil moisture by direct sampling, with tensiometers or a neutron probe or by calculation from meteorological data using formulae such as that of Penman (1948) or thornthwaite (1954). Penman's method only estimates the evaporation from a free water surface and Thornthwaite's formula is not very accusate for short periods. This paper describes the construction and performance of an hydraulic weighing bysineter that has been used successfully at Samaru since 1968.