Copyright © 2015 IJAIR, All right reserved 396 International Journal of Agriculture Innovations and Research Volume 4, Issue 2, ISSN (Online) 2319-1473 A Field Trial using Modified Alumina Refinery Residue to Beneficiate Composting at a Dairy Farm in Saudi Arabia Dr. Lee Fergusson Principal Consultant, Prana World Consulting, P.O. Box 1620, Oxenford, Queensland 4210, Australia Email: lee@pranaworldgroup.com. Abstract – Evidence suggests that alumina refinery residue, a byproduct of extracting alumina from bauxite, has properties which are beneficial to agriculture in general and to composting in particular. These contributions include increased moisture retention properties of soil and improved crop production. However, little evidence is available to confirm this claim in relation to Saudi Arabia or other Gulf States. This study therefore sought to investigate whether the addition of this type of residue to different dairy farm waste streams prior to composting had a beneficial effect on temperature and time to maturity of compost. Pure manure, manure plus bedding sand, leftover feed, and sludge from an on-site settling basin at a dairy farm in Al-Hofuf, Saudi Arabia were chosen as the four primary sources of organic matter for this large-scale field trial conducted during the autumn months of October to December. Results indicate that the addition of alumina refinery residue had no significant impact on the composting process, although minor benefits consistent with other research findings that could be attributed to the residue were observed. In this trial, differing beneficial results were more dependent on whether the compost was turned on a weekly or bi-weekly basis, andsome standard measures were effected as a result of the trial. Both six- and 12-week stability and maturity data are presented. Keywords – Composting, Dairy Farm Waste, Cow Manure, Alumina Refinery Residue, Saudi Arabia. I. INTRODUCTION In the last five to ten years, the rate and volume of residential and industrial composting in Saudi Arabia have increased significantly. While restricted by factors such as clean water supply and availability of carbonaceous green waste, composting is seen as a vital part of an increased recycling and sustainabilityeffort in the Kingdom. This trend is also reflected in the growth of a viable organic agricultural industry in Saudi Arabia, which in 2012 included 78 farms with 16,400 ha under cultivation in a global market which saw 16 million ha of organic agriculture under cultivation and $13 billion in sales in 2000 grow to 58 million ha under cultivation and $35 billion in sales by 2010 [1]. Hartmann et al. report that a further 2,200 ha in Saudi Arabia were undergoing conversion from non-organic to organic farming in 2012 [1]. However, Al-Turkimaintainsthe stability (i.e.,the resistance of compost to degradation) and maturity (i.e., the fitness of compost for land application and plant growth potential) of commercial compost remain questionable in Saudi Arabia, with 64% of 14 compost samples exceeding the upper limit of acceptable electrical conductivity (EC), 36% exceeding the optimal carbon-to- nitrogen (C/N) ratio of 25:1, 71% exceeding the maximum value for nitrification, 64% exhibiting signs of phytotoxicity, and three samples containing either faecal coliform, salmonella or staphylococci at concentrations above regulatory limits [2].For these reasons, a number of industry observers have pointed out there is a growing need for improved quality control standards for industrial composting operations in Saudi Arabia[1, 2, 3]; Alzaydi et al. in particular note the general paucity of reliable data on composting quality and practices in the Kingdom [3]. While data on methods and quality outcomes are limited, researchers have begun considering many unique approaches to the practice of composting in Saudi Arabia. For example, Alkoaik et al. evaluated the effectiveness of a bioreactor to compost date palm residues mixed with chicken manure and found that organic matter (OM), organic carbon (OC), C/N ratio, temperature and moisture contents of various mixing rates resulted in the production of suitable compost outcomes [4]. Similarly, Al-Bharakah et al. assessed decomposition rates of three types of green waste (i.e., dates trees, olive trees and maize), mixed with animal manure (i.e., sheep manure) with fiveinoculated microorganisms or so-called “organic activators” (i.e., Streptomycsaurefaciens, Trichoderma viridie, T. harzianum, Bacillicus subtilis, and B. licheniformis) at four different addition rates using standard windrows at a large-scale project in the El-Jouf region [5]. Al-Bharakah et al. found that temperature could be effectively monitored according to three standard phases of change during the 24-hour cycle and noted that all compost blends reached maturity by the twelfth week, bacterial counts reached their apex by the sixth week and decreased to stability by the seventeenth week, coliform counts reached zero by the sixth week, and that other physicochemical changes indicative of stability, such as pH, EC, OM, OC and C/N ratio, were achieved by the thirteenth week [5]. Sadik et al. conducted one of the largest composting trials at Al Kalidhiah farm in Riyadh [6]. This study investigated a variety of agricultural and animal waste byproducts (including quail, goat and sheep manure, and date, citrus and olive tree green waste), composed of compost biopiles with and without the addition of a biological activator composed of microorganisms, enzymes and yeast. The biopiles were turned every five days and were measured for variables such as temperature