The Kalman filter assimilation technique is applied to a simplified soil moisture model for retrieval of the soil moisture profile from near-surface soil moisture measurements. First, the simplified soil moisture model is developed, based on an approximation to the Buckingham–Darcy equation. This model is then used in a 12month one-dimensional field application, with updating at 1-, 5-, 10-, an...

Agricultural drought is defined as a shortage of moisture in the root zone of plants. Recently available satellite-based remote sensing data have accelerated development of drought early warning system by providing continuous soil moisture information in space and time. Nonetheless, the shallow sensing depth (top few cm) and uncertain accuracy of currentlyavailable satellite soil moisture retri...

Forest harvesting induces a step change in the climatic variables (temperature and moisture), that control carbon dioxide (CO2) production arising from soil organic matter decomposition within soils. Efforts to examine these vertically complex relationships in situ within soil profiles are lacking. In this study we examined how the climatic controls on CO2 production change within vertically di...

Satellite remote sensing observations have the potential for efficient and reliable mapping of spatial soil moisture distributions. However, soil moisture retrievals from microwave remote sensing techniques are typically complex due to inherent difficulty in characterizing the interactions among land surface parameters that contribute to the retrieval process. Therefore, adequate physical mathe...

Near-surface soil moisture is an important parameter in hydrological, meteorological and agricultural applications. Passive microwave observations, both airborne and satellite, can be used to infer near-surface soil moisture. The brightness temperature of the thermal radiation that crosses the soil–air interface is the product of the soil emissivity and the effective temperature. At L-band, the...

While the effect of soil temperature and moisture on soil CO2 efflux (Ec) has been widely investigated, the relationship between Ec and soil carbon (C), root, and stand parameters has not been comprehensively examined or quantified across extensive spatial and temporal scales. We measured Ec in loblolly pine (Pinus taeda L.) stands located on the South Carolina Coastal Plain across sites, seaso...

Several recent studies have highlighted the potential of Actively Heated Fiber Optics (AHFO) for high resolution soil moisture mapping. In AHFO, the soil moisture can be calculated from the cumulative temperature ( T cum ), the maximum temperature ( T max ), or the soil thermal conductivity determined from the cooling phase after heating ( λ ). This study investigates the performance of the T c...

abstract to optimal use of available water, irrigation scheduling is important to over scarcity of water resources in arid and semi-arid area. in this research to estimate of maximum allowable deficit (or: management allowed depletion) and irrigation scheduling of fodder mays based on canopy-air temperature difference, a field study was conducted in agricultural faculty of karaj. the lower limi...