Effect of animal manure and compost use on tield and sustainable cultivation of pepper

Compost, which is one of the most important factors of sustainable agriculture, is successfully used in vegetable cultivation. A lots of materials are used in making compost. In this study, the effects of composts obtained from fruit juice and tomato paste industry wastes on pepper and second crop spinach cultivation and changes in soil structure were investigated. Study started in 2020 with composting. Compost preparation was started by adding cow manure, urea, straw and lime to tomato, apple and grape wastes. The physical, chemical and biological properties of compost materials were investigated. Compost materials were used in pepper and spinach cultivation in different concentrations and mixtures. In the study, non fertilized control treatment, chemical fertilizers (NPKCaMg plus micro elements), 10 and 20 tons ha⁻¹ tomato, apple, grape and cow manure compost and compost + chemical fertilizers were applied. Pepper cultivation was carried out in compost-applied plots and the effects of compost on yield and quality of pepper was investigated. Spinach was grown as the second product after pepper cultivation and biomass measurement was made in spinach. At the end of the experiment, the physical and chemical properties of the soil samples taken from the composted plots were examined. The organic matter content of the compost used in the experiment varied between 55.58% and 68.82. pH and electrical conductivity of composts varied between 7.84 - 8.68 and 2.51 - 6.10 dS/m, respectively. N, P and K content of composts determined 2.71% - 4.09%, 0.58% - 0.88% and 38% - 3.26%, respectively. Bacterial content of composts determined between 4.75*106 and 3.60*107. While the marketable yield in pepper was 42.38 tons ha⁻¹ in control, it was 63.79 tons ha⁻¹ in 20 tons ha grape compost. The highest marketable yield was obtained from 20 tons ha⁻¹ cow manure compost + chemical fertilizer application (84.20 tons ha⁻¹). No relationship was found between composts and pH, brix and titretable acidity of pepper fruits. Biomass in spinach ranged from 7.03 tons ha⁻¹ (control) to 1.21 tons ha⁻¹ (20 tonnes ha⁻¹ grape compost). Compost had a significant impact on the development of spinach as second crop. At the end of vegetation, the organic matter content of the soil increased from 2.3% to 3.87%, nitrogen content from 0.094% to 0.128%, phosphorus content from 9.93 mg.kg⁻¹ to 14.17 mg.kg⁻¹ and potassium content from 121.33 mg.kg⁻¹ to 161.33 mg.kg⁻¹. As a result, high quality composts were obtained from tomato, apple and grape wastes and were used successfully in pepper and spinach cultivation. Composts also increased the physical and chemical structure of the soil. Grape compost was the most effective compost, followed by apple and tomato composts.