Low-cost microprocessed instrument for evaluating soil temperature profile Instrumento microprocessado de baixo custo para avaliação da temperatura em perfil de solo

This paper describes a low-cost microprocessed instrument for in situ evaluating soil temperature profile ranging from -20.0°C to 99.9°C, and recording soil temperature data at eight depths from 2 to 128 cm. Of great importance in agriculture, soil temperature affects plant growth directly, and nutrient uptake as well as indirectly in soil water and gas flow, soil structure and nutrient availability. The developed instrument has potential applications in the soil science, when temperature monitoring is required. Results show that the instrument with its individual sensors guarantees ±0.25°C accuracy and 0.1°C resolution, making possible localized management changes within decision support systems. The instrument, based on complementary metal oxide semiconductor devices as well as thermocouples, operates in either automatic or non-automatic mode.<br>Este artigo descreve um instrumento microprocessado de baixo custo para avaliação in situ da temperatura em perfil de solo na faixa de -20,0°C a 99,9°C com armazenagem de dados de até oito profundidades, de 2 a 128 centímetros. A temperatura do solo é de grande importância para o crescimento de plantas, absorção de nutrientes, fluxo de gases e estrutura. O instrumento desenvolvido encontra várias aplicações na área da ciência do solo, onde o monitoramento de temperatura do solo é requerido. Resultados mostram que a caracterização do instrumento e seus sensores individuais garantem uma acurácia de ±0,25°C e uma resolução de 1,0°C. Também proporciona a produtores ou pesquisadores a oportunidade do manejo localizado para sistemas de tomada de decisão. O instrumento é baseado em dispositivos semicondutores com tecnologia de óxido metálico complementar e termopares. E pode operar tanto no modo manual quanto no modo automático

Preface paper to the Semi-Arid Land-Surface-Atmosphere (SALSA) program special issue

International audienceThe Semi-Arid Land-Surface-Atmosphere Program (SALSA) is a multi-agency, multi-national research effort that seeks to evaluate the consequences of natural and human-induced environmental change in semi-arid regions. The ultimate goal of SALSA is to advance scientific understanding of the semi-arid portion of the hydrosphere-biosphere interface in order to provide reliable information for environmental decision making. SALSA approaches this goal through a program of long-term, integrated observations, process research, modeling, assessment, and information management that is sustained by cooperation among scientists and information users. In this preface to the SALSA special issue, general program background information and the critical nature of semi-arid regions is presented. A brief description of the Upper San Pedro River Basin, the initial location for focused SALSA research follows. Several overarching research objectives under which much of the interdisciplinary research contained in the special issue was undertaken are discussed. Principal methods, primary research sites and data collection used by numerous investigators during 1997-1999 are then presented. Scientists from about 20 US, five European (four French and one Dutch), and three Mexican agencies and institutions have collaborated closely to make the research leading to this special issue a reality. The SALSA Program has served as a model of interagency cooperation by breaking new ground in the approach to large scale interdisciplinary science with relatively limited resources