Rye Grass Forage Production and Water Use Improvements By Organo-Zeolitic Amendments in a Sandy Loamy Soil.

As in other regions around the globe, forage-based cattle production of the argentine Pampas region has move to more restrictive soil and climate environments because of the agriculture expansion in the more productive lands. In these forage systems, water and nutrient availability are the main limiting factors affecting forage production. The organo-zeolitic amendment (OZA) can increase forage yields and water use efficiency by improving the soil fertility conditions, especially water conservation and nutrient supply. The aim of the study was to evaluate the Rye grass (Lolium perenne L) response to an organo-zeolitic amendment application (OZA) under different soil water conditions. A pot experiment was performed during two month under greenhouse conditions. A randomized complete block design (RCBD) with four replications and factorial arrangement was used (2x2). The main factors were the amendment type (zeolite-clinoptilolite and feedlot residue) and water regime (field capacity and 60% of field capacity). Rye grass was sown in 1 L pots each, using a sandy loamy soil (Entic Hapludoll). Soil samples were obtained from representative forage-based cattle production systems of the western Pampas of Argentina (sub-humid-semi-arid climate conditions). Total biomass and water applied rates were evaluated at four sampling times during the experiment. Under no water restrictions (i.e. higher water availability), ryegrass biomass increased by 17 % (p <0.05) in the feedlot residue treatment, regardless of the sampling time or zeolite presence. A similar trend was observed in those treatments receiving water restrictions, where the highest biomass production was achieved in the feedlot residue treatments. Nevertheless, zeolite significantly reduced irrigation requirement, enhancing water use efficiency by 11%. Hence, organo-zeolite amendments should be taken into consideration as an economical and practical management tool for increasing forage production, water and nutrient use efficiency in marginal lands, leading to a more sustainability agro-ecosystems.