Effects of the Digestate Produced by the Bio-Digester EB.06019.LHT-MWINDA on the pH of Kimwenza-Mission Soil and the Growth of Amaranthus cruentus

Abstract

The evaluation of the effects of the digestate produced by the reactor EB.06019.LHT-MWINDA on the pH of Kimwenza soil and the growth of Amaranthus cruentus was conducted during the dry season (June-July 2019). Two treatments were used for the experiment: NPK (T1) and digestate (T2). The untreated soil was taken as a negative control(T0). The results obtained show that the digestate has a more neutralizing effect on the acidity of the Kimwenza-mission soil than the mineral fertilizer: the pH increased from 4.40 ± 0.33 to 9.28 ± 0.45 for T2 versus 5.19 ± 0.59 to 7.71 ± 0.29 for T1. The plants treated with T2 gave leaves with relatively more weight (1.8 ± 0.5g) than those obtained with T1 (1.06 ± 0.87g). It was observed that plants treated with digestate were taller (10,4 ±1,1m) than those with NPK (9,45 ±1,13m). The average number of leaves obtained from plants was 7.06 ; 6.36 and 5.97 respectively for T2, T1 and T0. These results are an indication that the digestate produced by the reactor EB.06019.LHT-MWINDA could be used for the amendment of the acidic soil of Kimwenza-Mission and therefore contribute to reducing significantly the use of synthetic agro-chemicals, hence decreasing residual environmental and human health hazards.