Effects of Diluted Biogas Slurry as Fertilizer on Growth and Yield of Tomato in Greenhouse

The objective of this study was to figure out the effects of different dilution ratios of biogas slurry on the growth and yield of tomato under the same N input in greenhouse cultivation. The experiment was carried out with greenhouse tomato grown in substrates, included low to high doses of biogas slurry as a top-dressing fertilizer during tomato growing period, and consisted of four treatments: (T1) pure biogas slurry, (T2) 1 biogas slurry + 1 water (v/v), (T3) 1 biogas slurry + 2 water (v/v), (CK) common compound fertilizer in eco-organic type soilless culture. In all four treatments, the nitrogen and irrigation water were provided with the same amount. The results were as follows: Biogas slurry increased the value of pH and EC in growing media. Biogas slurry could accelerate tomato growth and improve its yield and quality. The utilization of phosphorus and potassium was higher in biogas slurry than in CK. Among all treatments, T2 had achieved the highest stem diameter, fruit growth rate and the ratio of sugar to acid (10.48). The highest yield occurred in T3 and its yield per plant was 2.74% higher than that of CK. We recommend T2, T3 as a reference for tomato production in greenhouse.