Comparing the Deep Root Growth and Water Uptake of Intermediate Wheatgrass (Kernza®) to Alfalfa.

Abstract

AimsWater is the most important yield-limiting factor worldwide and drought is predicted to increase in the future. Perennial crops with more extensive and deep root systems could access deep stored water and build resilience to water shortage. In the context of human nutrition, perennial grain crops are very interesting. However, it is still questionable whether they are effective in using subsoil water. We compared intermediate wheatgrass (Kernza®) Thinopyrum intermedium, a perennial grain crop, to alfalfa Medicago sativa, a perennial forage, for subsoil root growth and water uptake.MethodsUsing TDR sensors, deuterium tracer labelling, minirhizotrons and the Hydrus-1D model we characterised the root distribution and water uptake patterns of these two perennial crops during two cropping seasons under field conditions down to 2.5 m soil depth.ResultsBoth crops grew roots down to 2.0 m depth that were active in water uptake but alfalfa was deeper rooted than intermediate wheatgrass. All experimental methods concluded that alfalfa used more water from below 1.0 m depth than intermediate wheatgrass. However, simulations predicted that intermediate wheatgrass used more than 20 mm of water after anthesis from below 1 m soil depth. Simulations confirmed the advantage of deep roots in accessing deep soil water under drought.ConclusionsIn regions with high groundwater recharge, growing deep-rooted perennial crops have great potential to exploit deep soil water that is often left unused. However, the road to a profitable perennial grain crop is still long and breeding intermediate wheatgrass (Kernza®) cultivars for increased root growth at depth seems to be a worthy investment for the development of more drought tolerant cultivars.

Biological Significance of Alfalfa in the Development of Organic Farming in South-Eastern Kazakhstan

“…The first control was the option without fertilization. The second control was applying mineral fertilizers to sugar beet at balance-sheet doses (Molyuga, 2007;Schweinzer et al, 2017;Clement, 2021). The principle of calculating fertilizer doses was as follows: for the average yield over the years obtained by applying the recommended doses of fertilizer, the additional use of fertilizers determined the further increase of the crop.…”

“…Alfalfa, like other legumes, plays an important role in the organic processing of agriculture. Past findings revealed that every million hectares occupied by alfalfa enriched the soil with a vast amount of nitrogen, requiring several factories to produce the mineral nitrogen fertilizers (Fageria and Baligar, 2005;Schweinzer et al, 2017;Clement, 2021). It is critical for saving energy and economic costs for the production of nitrogen fertilizers.…”

“…It is also rich in micro-elements, which are necessary to physiological processes in animals and birds (Schweinzer et al, 2017;Paczkowski et al, 2018). Lucerne provides high yields, enriches the soil with organic matter, improves its physical and physio-chemical properties, enhances the life activity of helpful microorganisms, soil fertility, and crop yield, and is, therefore, an indispensable precursor in the crop rotation (Gekhaev, 2008;Kozyrev and Farniev, 2010;Clement, 2021). Nitrogen fixed through legume pastures and forages is an essential contribution (Peoples et al, 2015) and provides a substitute for chemical fertilizer to increase soil nitrogen availability that can promote non-legume forage production in grasslands (Yuan et al, 2016).…”

Deep soil water depletion and soil organic carbon and total nitrogen accumulation in a long‐term alfalfa pasture

“…Guan et al (2016) indicated that SOC storage in the 0-200 cm soil layer increased by 14.6-24.1 Mg C ha À1 under the alfalfa, bush clover and milk vetch pastures over 7 years. Deep soil resources contributed substantially to the production and ecological functions of dryland ecological systems (Clément et al, 2022;Lynch & Wojciechowski, 2015). Yang et al (2020) and Lan et al (2021) all proved the positive effects of apple orchard on soil carbon storage to the depth of 1000 cm in the CLP.…”