NUTRIENTS CONTENTS AND PHYSICAL PROPERTIES OF HOT COMPOSTING OF LOCAL ORGANIC WASTE IN DUHOK CITY_ IRAQ KURDISTAN REGION
The main objective of this research was to evaluate the different organic residue available in local area in Duhok province in Iraqi Kurdistan region for making four different hot compost during 18 days and evaluating some there physical and chemical quality indices. Result revealed that the first heap that formed from wheat hey and straw, sheep manure, brown garden residue, chicken manure, fruit and vegetable scrapes, contains significantly the lowest value of soluble calcium 6.46± 0.29 to 6.93±0.48 meq/l and potassium 4.39± 0.04 to 5.87± 0.03 meq/l, while has the same contents of soluble magnesium and sodium meq/l and the lowest EC values. The second heaps that formed from brown grass clipping, fish meal, pine needle, green grass clipping, vegetable and fruits scrapes is better than first heaps for their Ca and K content but have the highest value EC of 2.66± 0.02 ds.m-1. The third heap which formed from carton board and papers, slaughter waste, saw dust, brown garden residue, vegetable and fruit scrapes and forth heap which is a mixture of three above mentioned heaps in sequential are supreme significantly in their content of almost studied parameters. The lowest value of organic matter was observed in first heaps of 30.77±0.8%, while the highest value was recorded in forth heaps of 64.36±5.43%.the total nitrogen was obtained in third hep of 3.16±0.25%. the P range in all heaps are in allowable ranges, the fourth heap being the supreme on its total P contents, then second heap and ranges between 0.47±0.02 to 0.85±0.02. The C/N ratio varies from 10.45±1.6 in third heap to 25.65±1 in first heap. The bulk density ranges between 200±5- 470±10 kg.m-3of and the bulk density of third compost heap is significantly lower than the fourth heap which is significantly lower than first and second heaps. The porosity of various constructed heaps ranges between 59.20±0.7 to 68.29±0.86%. The final texture of finished matured compost by hot composting during 18 days is so fine to be considered as soil conditioner that improve almost soil chemical, physical, and biological properties of soil. So, it concludes that the third and fourth heaps are better than first and second heaps of all studied parameters.
Mature Compost, Carbon/Nitrogen Ratio, Organic Matter, Total Nitrogen, Porosity, Moisture Content