Root zone soil moisture redistribution in maize (<i>Zea mays</i> L.) under different water application regimes

Abstract

Soil moisture availability to plant roots is very important for crop growth. When soil moisture is not available in the root zone, plants wilt and yield is reduced. Adequate knowledge of the distribution of soil moisture within crop's root zone and its linkage to the amount of water applied is very important as it assists in optimising the efficient use of water and reducing yield losses. The study aimed at evaluating the spatial redistribution of soil moisture within maize roots zone under different irrigation water application regimes. The study was conducted during two irrigatation seasons of 2012 at Nkango Irrigation Scheme, Malawi. The trials consisted of factorial arrangement in a Randomised Complete Block Design (RCBD). The factors were water and nitrogen and both were at four levels. The Triscan Sensor was used to measure volumetric soil moisture contents at different vertical and lateral points. The study inferred that the degree of soil moisture loss depends on the amount of water present in the soil. The rate of soil moisture loss in 100% of full water requirement regime (100% FWRR) treatment was higher than that in 40% FWRR treatment. This was particularly noticed when maize leaves were dry. In 100% FWRR treatment, the attraction between water and the surfaces of soil particles was not tight and as such "free" water was lost through evaporation and deep percolation, while in 40% FWRR, water was strongly attracted to and held on the soil particles surfaces and as such its potential of losing water was reduced.

Soil weight determination for optimal growth and yield performances of pot-grown maize

“…The impediment might have affected soil moisture and nutrient availability and distribution within the soil and to the plant roots zone, thereby limiting plant growth and yield performances (Mthandi et al, 2013). The 'dwarfing' responses due to root restriction as observed in maize grown in 5, 10 and 20 kg pots had been attributed to hydraulic and non-hydraulic factors (Hurley and Rowarth, 1999;Yong et al, 2010).…”

Green water availability and water-limited crop yields under a changing climate in Ethiopia

“…( 7)) infiltrates into the soil and refills the available soil storage 𝑉 𝑡 [mm] = 1000𝑍(𝜃 𝑠𝑎𝑡 − 𝜃 𝑡−1 ), where 𝜃 𝑠𝑎𝑡 [m 3 m -3 ] and 𝜃 𝑡−1 [m 3 m -3 ] are volumetric soil moisture content at saturation and on the previous day (respectively), and Z [m] is the soil depth. We considered that the top 60 cm homogeneous soil layer contains the majority of the root biomass (e.g., Fan et al, 2016;Mthandi et al, 2013) which plants experience moisture stress. For all four cereal crops studied, the value of 𝑓 was set to 0.55 following Allen et al (1998).…”