2017 ASHS Annual Conference

Nutrient and water uptake by plant roots are related to availability of these critical inputs in the soil. Root characteristics such as density, depth, length, number of root hairs and root tips are considered important to uptake of water and nutrients. Root growth and proliferation under adequate watered and drought stress conditions varies among species. Plants increase water uptake by developing large and deep root systems. Evidence suggests that it is quality, i.e. the distribution and structure, and not quantity of roots that determines the most efficient strategy for extracting water during the growing season. The objectives of this study was to determine the differences in root distribution and biomass on rate of nutrient uptake under two water treatments using two different types of soils among grass species Bouteloua curtipendula and Bouteloua gracilis. The two species of grass were germinated in two different soils, clay and sand, and treated with adequate water (100% of needed water) and reduced watered (25% of adequate water). The length, surface area, volume of the roots, and the biomass have been measured. Also, the plant tissues, Na, P, Ca, Mg and k, have been analyzed to determine the ability of the root to absorb the minerals and water uptake from the different types of the soil among the species, water potential has been measured for the both species after the time of irrigation. Soil analysis and soil texture and PH measurements have been done. The result showed significant effects of soil type between species when adequately watered as compared to those with water deficiency. Bouteloua curtipendula had its highest rate of growth and biomass in the clay soil with adequate water. It had the lowest growth rate and biomass when grown in the sand with reduced water. Bouteloua gracilis had the highest growth rate and biomass in the clay with adequate water as well when compared to the other treatments within the species. In comparison between the two species, Bouteloua gracilis showed very significant differences in the root system growth and distribution as well as the rate of nutrient uptake and total biomass with both types of soils and with the two water treatments where the Bouteloua curtipendula has the lost root growth rate under water deficiency. In conclusion, the soil texture and soil water capacity have the major influence on root distribution and the rate of nutrient uptake. Plant root growth and nutrient uptake are highly influenced by variation in the environment.