Soil moisture dynamics modeling considering multi-layer root zone

Abstract

The moisture uptake by plant from soil is a key process for plant growth and movement of water in the soil-plant system. A non-linear root water uptake (RWU) model was developed for a multi-layer crop root zone. The model comprised two parts: (1) model formulation and (2) moisture flow prediction. The developed model was tested for its efficiency in predicting moisture depletion in a non-uniform root zone. A field experiment on wheat (Triticum aestivum) was conducted in the sub-temperate sub-humid agro-climate of Solan, Himachal Pradesh, India. Model-predicted soil moisture parameters, i.e., moisture status at various depths, moisture depletion and soil moisture profile in the root zone, are in good agreement with experiment results. The results of simulation emphasize the utility of the RWU model across different agro-climatic regions. The model can be used for sound irrigation management especially in water-scarce humid, temperate, arid and semi-arid regions and can also be integrated with a water transport equation to predict the solute uptake by plant biomass.

Moisture dynamics and irrigation modelling in apple (Malus domestica) trees using CROPWAT model in temperate region of India

“…The variation of moisture depletion at different depth was also determined. It is observed that the maximum depletion of moisture takes place at the top 16 cm layers of soil and is considerably less in the lower layers (Kumar et al 2013a). Similar trend was observed over the entire study period.…”

“…The results of moisture depletion are shown in Fig 1 for the period of 640-805 and 670-685 DAP. It is evident from the Fig 1 that there is minimum depletion of moisture in the initial months of the study period due to lesser plant canopy (Shankar et al 2012, Kumar et al 2013a. At the development stage of plant there is a considerable increase in the moisture depletion as the temperature has started rising and the plant has attained maturity stage.…”

“…Water is most precious gift of nature, essential for human and animal life (Clothier 1990, Coelho and Or 1996, 1999 and plays an important role for plant growth (Richards and Wadleigh 1952, Wesseling and Feddes 2006, Kumar et al 2012, Kumar et al 2013a. Water resources play an important role as a catalyst for the economic development of a nation.…”

“…Drip irrigation is one of the advance irrigation methods and apply required amount of water directly in the root zone at frequent intervals which may save sufficient quantity of water as compared to surface method of irrigation (Kumar et al 2014a). Deficiency of water in the root zone of soil results in reduced plant growth and affects the crop yield, thus objective of irrigation is to maintain adequate moisture content in the root zone, such that crop yield is not affected adversely (Green et al 2006, Kumar et al 2012, Kumar et al 2013aKumar et al 2014). Initial studies of the unsaturated (vadose) zone focused primarily on water supply studies, inspired in part by attempt to optimally manage the root zone of agricultural soils for maximum crop production temperature, humidity, rainfall, sunshine and wind speed was collected from the Division of Agronomy, other data was determined from the empirical formulas given in the FAO-56 manual.…”

A Dynamic Variation of Root Water Uptake in Drip Irrigated Paddy

“…A better understanding of Root Water Uptake (RWU) is essential for improving irrigation and fertigation scheduling in drip irrigation (Green and Clothier, 1999). The RWU is a dynamic process influenced by many factors such as plant characteristics, cropping pattern, water content availability, soil hydraulic properties and environmental conditions respectively (Kumar et al, 2013). Generally, it is difficult to obtain RWU directly from the field experiments.…”