Effect of applying coconut fiber (Cocos nucifera L.) on storage and water use efficiency in an Alfisol seeded with ryegrass (Lolium multiflorum L.) and its toxicity in lettuce (Lactuca sativa L.)

Abstract

The search for techniques that allow a more efficient use of water is a global task, since this resource is increasingly scarce and its quality is constantly deteriorating. The objective of this study was to determine the effect of applying coconut fiber CF on physical-hydric parameters of the soil and its water use efficiency (WUE). The effects of coconut fiber (CF) were assessed on water consumption, water use efficiency and aerial and root biomass of Italian ryegrass (Lolium multiflorum L.). In addition, it was also evaluated whether CF causes toxic effects on lettuce seeds (Lactuca sativa L.). Treatments were established according to the proportion of CF and soil in g g^-1 soil CF: T1 = 1:80, T2 = 1:40 and T3 = 1:20, and a control treatment (T0 = no substrate). Additionally, 3 charges of water (100, 75, 50 % of field capacity) were established. Results showed that the best treatment for water consumption was T3-50 (377.8 ml), for WUE the best treatment was T3-100 (8.52 kg DM m^-3), for aerial biomass it was T3-100 (4.59 g MS) and in the case of root biomass the best treatment was T3-100 (1.92 g MS). It was concluded that the addition of coconut fiber substrate to the mix improves the physical and hydrological characteristics of degraded soil. There were no toxic effects on lettuce among the applied rates of CF. The germination index (IG) ranged from 124.82 to 156.03 % and the best treatments were T3 and T2.