In this paper, mathematical models are presented to study the thermal behavior of crops (cabbage and peas) for open sun drying (natural convection) and inside the greenhouse under both natural and forced convection. The predictions of crop temperature, greenhouse room air temperature and rate of moisture evaporation (crop mass during drying) have been computed in Matlab software on the basis of...

Numerous efforts have been made to develop various indices using remote sensing data such as normalized difference vegetation index (NDVI), vegetation condition index (VCI) and temperature condition index (TCI) for mapping and monitoring of drought and assessment of vegetation health and productivity. NDVI, soil moisture, surface temperature and rainfall are valuable sources of information for ...

This paper presents a case study applying GNSS signals, which were reflected on the ground surface (soil, vegetation surface) to derive soil moisture and vegetation height data over a wheat crop field. The GPS antenna was installed at a height of 2.51 m. Soil moisture was retrieved as long as the vegetation height was lower than ∼20 cm. However, with a further increase in plant height, it was n...

As one of soil dynamics properties, soil moisture content is an important factor of soil fertility which counts for much to crop growth situation and scientific irrigation management. A design plan of regional spatial variation of soil moisture measurement was introduced. Its main job includes the use of differential GPS technology for each sampling points in farmland, collecting data of high-p...

Timely irrigation of cotton has been shown to increase yields, but almost every year producers and researchers observe poor plant development even with irrigation under some condition. Adequate moisture must be present when the cotton crop needs it, but saturated soil conditions deprive the roots of necessary oxygen. Current recommendations lack detail concerning irrigation management. Use of t...

Water shortage is a serious constraint on crop production on the North China Plain (NCP), where cropland is mainly irrigated by pumping groundwater from alluvial aquifers. To develop a sustainable ground water and irrigation management strategy, we developed a three-layer soil water balance model which is easy to use, robust, but physically based simulation tool. The model successfully simulate...

Lori M. Bruce Hrishikesh D. Tamhankar Department of Electrical and Computer Engineering, Mississippi State University, Mississippi State, MS 39762 Experiments were conducted to examine the use of spectral reflectance curves for discriminating between plant species across moisture levels. Weed species and soybean were grown at three moisture levels, and spectral reflectance data and leaf water p...

Weeds represent a global agronomic problem that threatens the productivity of cultivated crops. Weeds compete with cultivated crops for the available moisture, nutrients and light. Consequently, weeds significantly reduce either crop yield or quality. Control of weeds is essential to maintaining the production of economic crops. Weed control may be achieved either through manual eradication or ...