Sustainable maize production by urban biowaste products

For sustainable agriculture productivity and environmental quality, composts are considered as substitutes of chemical fertilizers. They are applied to soil at tens-hundreds dry matter ton ha-1 yearly dose to contribute organic C and N and minerals. Hereinafter, municipal biowaste compost and its hydrolysate products are reported to enhance maize plant growth and productivity at much lower dose. The compost was obtained from a mix of food, gardening residues and sewage sludge. Afterwards, it was hydrolyzed to yield soluble substances (SBO) which were separated from the insoluble residue (IOR). The compost, SBO and IOR contained organic matter (om) and mineral elements (me) in 2.7-0.29 om/me w/w ratio, with SBO and IOR characterized by the highest and lowest weight ratio respectively. The three materials (compost, SBO and IOR) were applied to soil in open field and in pots in hydroponic conditions at 7-9078 kg ha-1 dry matter dose. Urea as conventional fertilizer was used in separate trials at 200 kg ha-1 for comparison. Plant performance indicators were leaf photosynthesis, plant growth, and kernel production and quality. The results demonstrate the higher performance of SBO at 50-140 kg ha-1 both in open field and pot trials. Over double kernel production was obtained in open filed by the plant grown on soil treated with 50 kg ha-1 SBO compared to the control soil plant. The pot trials support the importance of the SBO organic matter coupled to mineral elements. The results prospect urban biowastes derived products as viable auxiliaries for ecofriendly sustainable agriculture.