Animal Based Biogas Digestate Application Frequency Effects on Growth and Water -Nitrogen use Efficiency in Tomato

Abstract

Anaerobic digestion residues (digestate), has low nutrients concentration in nature and known as new type valuable organic fertilizers, that should be applied frequently to meet the plant growth. In present study, the performance of animal based biogas digestate frequencies (4 d, 6 d, 8 d) was evaluated and compared with conventional mineral fertilizer (CF) and no fertilizer (CK) in greenhouse during 2017 and 2018. The application of digestate and mineral fertilizer were mixed with water via two holes on both sides of plant. All treatments (digestate application frequencies is 4 d, 6 d, 8 d, CK and CF) were irrigated with similar method and the same amount of water. The plant height, stem diameter, biomass, yield, quality and water use efficiency (WUE) of tomato were measured, and the nitrogen content in each 10 cm soil layer and the nitrogen use efficiency (NUE) were assessed. The results showed that the growth, yield and tomato quality in 4 d and 6 d treatments were both superior than CF treatment, and the digestate application frequencies in 4 d and 6 d treatments can satisfy the demand of tomato growth. The 4 d digestate frequency had the highest total biomass, yield, fruit quality and WUE among all treatments, also had higher NUE, therefore, the digestate application frequency of 4 d was best and can be used as an appropriate option in digestate agricultural use under hole irrigation.