1. Results and Discussion
Recycling of Agricultural Wastes Using Composting: Windrow Method G. CAYCI, A. COLAK, S. S. OK, A. BARAN, Z. DILAVER, C. TEMIZ, C. TEKIN  Agricultural Faculty of the Ankara University, Ankara, Turkey Ankara University
Results and Discussion
Abstract
Table 2. Total plant nutrient contents of the composted materials
MATERİALS N P K Ca Mg Fe Zn Mn Cu %
(ppm)
DAIRY CATTLE
1,39
0,36
1,09
9,23
1,52
2,16
170
842 6
CHICKEN
1,41
1,49
1,32
11,33
1,72
1,46
402
668 10
MIXTURE
1,65
0,54
1,55
10,88
1,91
2,13
212
1168
VEGETATİVE
1,1
0,16
0,9
6,62
1,62
1,67
112
726 4
SHEEP
0,85
2,19
9,32
2,72
1,38
286
902 8
Soil physical and chemical characteristics are very important for sustainable agriculture and soil quality. Organic matter is a component of soil affecting extremely positive soil physical, chemical and biological properties, and it is also an indispensable element of sustainable farming practices. Many materials can be used as an organic matter sources, and one of them is compost. Composting is the aerobic decomposition of organic materials under high temperatures. Composting is a process actually ongoing in nature, and it is a nutrient recycling in the ecosystem. Products obtained by composting improve soil physical and chemical characteristics. In this study, wastes produced during agricultural production in farm affiliated with Agricultural Faculty of Ankara University were composted using by windrow method. Cattle, sheep and chicken litters, vegetative residues and a mixture including all of the wastes were used as compost windrows. The length, width and height of windrows were nearly 100m, 3m and 1m, respectively. Windrows were periodically turned by compost turner, and temperature, moisture and C/N ratios were measured during composting period. Composting was terminated nearly at the end of four months considering the temperature, physical appearance, C/N ratios in piles. Afterwards, organic matter content, total organic C, N, P, K, Ca, Mg, Fe, Mn, Zn, B, Cu, Cr, Cd, Pb, Sn and Hg, and water soluble P, K, Ca, Mg, Fe, Mn, Zn, B, Cu, and moistures retained at pF0, pF2,54 and pF4,2 were determined in all composts. Also, phytotoxicity tests were done in composts. Then composts were evaluated for agricultural use in terms of physical and chemical characteristics.
C/N changes in materials during composting
Compost piles were sampled six times between June 8 and October 14, 2015 taking into account the temperature in the compost piles. Organic carbon and total nitrogen analyses were done in the sampled materials to determine C/N ratio during composting. C/N ratio and temperatures in piles were evaluated as indicators of maturity of compost (Ko et al. 2008). Changes in C/N ratios in the sheep manure compost were presented (Figure 1).
Total plant nutrient contents of composted materials were evaluated it was seen that the mixture material has the highest level with 1,65% with regard to total nitrogen while the lowest was found in the vegetative material as 1,10% (Table 2).
Total phosphorus contents of the composted materials ranged 1,49% to 0,16%. As we considered potassium contents of materials the highest content was in the sheep manure with 2,19% whereas the lowest level was found in the vegetative material as 0,90%. Total nitrogen, phosphorus and potassium contents in solid beef cattle manure were determined as 3,17-16,30 kg /tons, 0,90- 2,71 kg /tons and 3,17-7,70 kg /tons, respectively (Anonymous 2016).
Calcium contents of composted materials were high in all materials. It changed between 6,92% and 11,33%. Magnesium contents of samples were between 1,52% and 2,72%. Iron contents of samples were high as well and it changed between 1,38% and 2,16%. On the other hand, heavy metal contents of all the composted materials were found under the limit values with regard to regulation of Turkish Ministry of Food, Agriculture and Livestock.
Figure 1. Changes in C/N ratios in the sheep manure during composting in sampling periods
Temperature changes in materials during composting
Temperature readings were done in the compost piles totally ten times during nearly four months composting process (Photo 2).
Table 3. Water soluble plant nutrient contents of the composted materials
Material and Method
MATERİALS P K Ca Mg Fe Zn Mn Cu B
(ppm) %
DAIRY CATTLE
70,60
1626
427,30
199,60
2,20
3,40
0,30
0,20 2
CHICKEN
456,50
2855
394,20
202,30
11,10
5,30
0,90
1,00
6,5
MIXTURE
167,10
2387
379,60
171,70
3,20
0,70
1,8
VEGETATIVE
89,90
664,30
527,00
131,50
5,60
3,30
0,10
0,3
SHEEP
244,30
8557
453,90
236,90
3,80
4,00
3,3
Figure 2. Changes in temperatures in the chicken manure in different days
In this study, cattle, sheep and poultry litters and some vegetative residues produced in the Haymana Research and Practice Farm of Agricultural Faculty of Ankara University were used for composting.
The Formation processes of five different compost piles consisting of cattle, sheep, poultry litters, vegetative residues and a mixture including all of the wastes were followed during research period. Composting was done in aerobic conditions by windrow method (Photo 1). Piles were covered by plastic covers in order to conserve composting materials from precipitation and wind in winter period. (Photo 2).
Composting method
As temperature readings in chicken manure compost pile were evaluated it was seen that initial temperature was 26 C° in the pile. However pile temperatures increased within the short time, and temperature reached to the maximum value in composting as 63 °C at the forty seventh day. After that pile temperatures continuously decreased and reached the minimum value as 21 °C at the end of composting.
Water soluble plant nutrient contents of the composted materials were examined it was shown that the highest phosphorus level was 456 ppm in the chicken manure while the lowest was 89 ppm in the vegetative material. The highest level water soluble potassium content was determined in the sheep manure with 8557 ppm whereas the lowest was found in vegetative material as 664 ppm. Calcium, magnesium and sodium contents of the composted materials changed between ppm, ppm and ppm, respectively (Table 3).
Water soluble iron, zinc, manganese, copper and boron contents of the composted materials ranged 2,20 to 11,10 ppm, 3,30 to 5,30 ppm, 0,30 to 0,90 ppm, 0,10 to 1,00 ppm and 0,3 to 6,5 ppm, respectively (Table 3). It was seen that composted chicken manure was richer than other materials in terms of water soluble micro plant nutrients.
Some physical and physico-chemical properties and water soluble plant nutrient contents of composted materials
Table 1. Some physical and physico-chemical properties of the composted materials
MATERİALS
ORGANİC
SATURATION
FIELD
WILTING
GERMINATION
MATTER(%)
CARBON (%)
(%)
CAPACITY (%)
POINT (%)
INDEX (%)
DAIRY CATTLE
41,97
20,17
81,94
34,32
28,14 97
CHICKEN
24,07
14,41
81,38
32,68
26,81 91
MIXTURE
29,32
13,78
78,87
33,07
26,26 74
VEGETATIVE
29,04
14,83
76,37
27,53
21,88 93
SHEEP
40,42
24,56
88,57
45,55
41,08
Physico-chemical properties of composted materials were examined it was shown that the highest organic matter content was in the composted cattle manure with 41,97% while the lowest content was obtained in the composted chicken manure with 24,07%. Composted sheep manure was in the second rank in all samples as 40,42% in terms of organic matter content. Loses in organic matter content during composting was the highest in the chicken manure with 60,5% and the lowest was found in the sheep manure as 18,5% as compared with initial values (Table 1).
As organic carbon contents of samples were considered, it was shown that the highest content was in the composted sheep manure with 24,56% while the lowest was in the composted chicken manure as 13,78%. The ratio of organic matter content to organic carbon content was the highest in the mixture sample with 2,12 while the lowest ratio was determined in the sheep manure as 1,64. The average value of all composted materials were considered the ratio was calculated as 1,89.
The maximum retained water content called as saturation were taken into consideration it was seen that saturation values of the composted materials changed between 76,37% and 88,87% (Table 1). The highest field capacity value was determined in the composted sheep manure as 45,55% whereas the lowest value was measured in the composted vegetative material with 27,53%. Permanent wilting point values of samples were examined the highest value were found in the composted sheep manure as 41,08% while the lowest was determined in the composted vegetative material with 21,88%. It is evaluated that composted materials decomposed well and coarse materials were less in the samples because of field capacity and permanent wilting point values close to each other in all the samples.
The highest germination index was determined in the composted cattle and sheep manures with 97%. On the other hand, the lowest was in the composted vegetative material as 74% (Table 1). High germination index values are considered as a good property for composted materials with regard to compost maturity.
Conclusion
This study demonstrated that all kinds of organic wastes produced in the Haymana Research and Practice Farm can be composted.
 It should be known that large- scale composting conditions such as windrow method are more difficult than small-scale composting in which conditions much easier to be controlled.
Particularly, providing of appropriate C / N ratios in the initial piles after that sustaining proper moisture levels at the thermophilic period will affect the quality of the product and duration of composting.
At the beginning in order to increase the C/N ratio and reduce high moisture content in the chicken manure pile is needed wood chips or straw as bulking agent and carbonous material for composting.
Organic matter losses changed between 18,5% and 60,5% depending on the composted materials during composting compared to initial contents.
Making of a waste management plan and determining responsible personnel are necessary for storing, transferring and composting of these wastes on a regular basis for successful production.
Photo 1. Formation of piles using by wheel loader
Photo 2. Protection process of compost piles from precipitation and wind in winter time
Photo 3. Five different composted materials after composting
Compost Analyses
REFERENCES
Anonymous (2016). Web sitesi: Erişim tarihi
Anonymous Diagnosis and Improvement of Saline and Alkalin Soils. U.S. Salinity Laboratory Staff, Agricultural Hanbook, No. 60.
Bremner, J.M., Mulvaney, C.S. (1982): Methods of soil analysis, part 2 chemical and microbiological properties,
DIN Torf für Gartenbau und Landwirtschaft
Kacar, B., Bitki ve Toprağın Kimyasal Analizleri: II. Bitki Analizleri, Ankara Üniv. Ziraat Fakültesi Yayınları: 453, Uygulama Klavuzu:155.
Kirven, D.M “An Industry Viewpoint: Horticultural Testing is Your Language Confusing” Proc. of the Sym. Interpretation of Extraction and Nutrient Determination Procedures for Organic Potting Substrates,
Nelson, D. W., and L. E. Sommers Total carbon, organic carbon and soil organic matter. In: Methods of Soil Analysis Part II, ed. A. L. Page, pp. 539–579. Madison, WI: ASA-SSSA.