Reuse of Pruning Waste from Subtropical Fruit Trees and Urban Gardens as a Source of Nutrients: Changes in the Physical, Chemical, and Biological Properties of the Soil

A field experiment was conducted on the Andalusian coast (Granada, Southern Spain) to study the time course of nutrient release into the soil after the addition of bagged pruning waste from subtropical orchard trees (avocado, cherimoya, and mango) and urban garden waste over three two-year periods. N, P, and K concentrations were greater in the garden waste, whilst avocado and cherimoya pruning waste registered the highest values for Mg. In general, micronutrient contents were low in all waste, especially Cu. Macronutrient release followed a three-phase dynamic: fast initial release, intermediate stabilization, and final increase. Garden waste showed a similar time course in all three trees and released greater concentrations of K and P. The annual decomposition rate factor k was negative for N and Ca in the avocado tree, indicating strong biological activity in this plot. Avocado, cherimoya, and garden waste showed a good microbial degradation, improving soil quality by increasing carbon and nitrogen contents as well as soil microbial activity. As for the mango tree, its special microclimatic conditions appeared to favor waste photodegradation, thus eliminating nutrients that were not incorporated into the soil. Soil enzymatic activities increased in the avocado and cherimoya trees with the addition of all waste. In the mango tree, only an increase in urease was detected after the addition of garden waste. Our results suggest that the time course of organic waste in different subtropical trees grown on similar soils is significantly conditioned by the microclimatic characteristics.

Co-Digestion of Kitchen Waste with Grass and Leaves after Hyperthermophilic Pretreatment for Methane and Hydrogen Production

The study investigated co-digestion batch experiments using kitchen waste (KW) and garden waste (GW) collected from individual households. Grass and leaves were first subjected to a 3-day hyperthermophilic pretreatment at 70 °C and 80 °C and then co-digested with kitchen waste at 35 °C and 55 °C. The hyperthermophilic pretreatment resulted in the solubilization of organic material with the release of fatty acids, whereas the biogas yield was negligible. In the second stage, the greatest methane yield of 387 NmL/gVS was achieved for the mono-digestion of leaves, whereas the co-digestion of grass with 50% KW gave the highest hydrogen production of 88 NmL/gVS. Considering the overall process performance, the best operating conditions were established using a 3-day hyperthermophilic pretreatment at 70 °C, followed by co-digestion at 55 °C in the second stage for the mixture of 25% garden waste with 75% KW.

Pembuatan Kompos Sampah Dapur dan Taman dengan Bantuan Aktivator EM4

<p>Pembuatan kompos dari sampah dapur dan taman dengan bantuan <em>effective microorganism</em> (EM4) dan <em>microorganism local</em> (MOL) telah dilakukan. Tujuan dari kegiatan ini adalah memanfaatkan sampah yang ada di sekitar untuk dijadikan barang yang lebih berguna. EM4 merupakan kultur campuran dari mikroorganisme yang menguntungkan yang mengandung mikroorganisme fermentasi dan sintetik yang terdiri dari bakteri Asam Laktat (<em>Lactobacillus Sp</em>), bakteri Fotosentetik (<em>Rhodopseudomonas Sp</em>), <em>Actinomycetes Sp</em>, <em>Streptomyces Sp</em> dan Yeast (ragi) dan Jamur pengurai selulose. Bahan ini membantu fermentasi bahan organik tanah menjadi senyawa organik yang mudah diserap oleh akar tanaman. Proses pembuatan kompos dilakukan dengan mencampurkan sampah dapur dan taman dengan penambahan EM4. Proses fermentasi dilakukan variasi waktu 10, 14, 21, 26 dan 32 hari. Hasil pengamatan menunjukkan bahwa semakin lama fermentasi kompos yang dihasilkan semakin baik dimana daun telah hancur berubah bentuk seperti tanah.</p><p><strong><em>Kitchen and Garden Waste Composting using EM4 Activator. </em></strong><em>Composting of kitchen and garden waste with the help of effective microorganisms (EM4) and microorganism local (MOL) has been carried out. The purpose of this activity is to use the waste to become more useful items. EM4 is a mixed culture of beneficial microorganisms. This material contains microorganisms consisting of lactic acid bacteria (Lactobacillus Sp), photosynthetic bacteria (Rhodopseudomonas Sp), Actinomycetes Sp, Streptomyces Sp, and yeast, and cellulose-decomposing fungi. This activator helps break down soil organic matter into organic compounds that are easily absorbed by plant roots. The composting was done by mixing kitchen and garden waste with the addition of EM4 and MOL. The fermentation process was carried out in variations of 10, 14, 21, 26, and 32 days. The results showed that the longer the fermentation time the better the compost was produced indicating by the leaves had crumbled into shape like the soil.</em></p>

Obtaining and Use of Compost from the Organic Component of Household Waste

The relevance of the study is conditioned by the need to develop and implement technological solutions for processing food and garden waste into compost. The purpose of this study is to investigate the methods of obtaining compost from the organic component of household waste and analyse composts for compliance with the requirements for their use as fertilisers. Theoretical research on the issues of the application of an organic component of a firm household waste as a raw material for compost production is carried out. According to statistical information on the accumulation of household waste in Ukraine, the amount of food and garden waste in the regions of Ukraine has been calculated. Modern methods of industrial processing of food and garden waste into compost are analysed, and the most effective technology from the standpoint of ecology and energy saving is determined. Data on the influence of composted digestate on crop yields are given. Composts were analysed for compliance with the requirements for their use as fertilisers The data show that the difference between the content of heavy metals in the composted digestate and compost from food waste is not significant and both composts meet the German quality requirements of compost. Data on the influence of composted digestate from food waste on the growth of winter grain yields are given. It has been found that the use of composts can supplement conventional mineral fertilisers in crop cultivation. The practical significance of the study is to determine the prospects of obtaining fertiliser from the organic component of solid waste and to determine its effectiveness when applied to the soil