The 1 th International and The 4 th National Congress on Recycling of Organic Waste in Agriculture April 2012 in Isfahan, Iran

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1 The 1 th Interntionl nd The 4 th Ntionl Congress on The Effect of Prticle Size nd Composting Period on (C/N) Rtio of Dte- Plm Wste Min Mortzvi 1, Ahmd Mohmmdi Ghehsreh 2 nd Mhmoud Klsi 3 1. M.Sc. Student, Deprtment of Soil Science, Fculty Of Agriculture, Islmic Azd University, Khorsgn Brnch, Isfhn, Irn. 2. Assistnt Professor, Deprtment of Soil Science, Fculty Of Agriculture, Islmic Azd University, Khorsgn Brnch, Isfhn, Irn. 3. Professor, Deprtment of Soil Science, Fculty Of Agriculture, Islmic Azd University, Khorsgn Brnch, Isfhn, Irn. m.mortzvi139@yhoo.com ABSTRACT: Solid wstes generted from griculturl ctivities such s crop residues require specil ttention for its disposl. Applictions of these wstes into soilless systems s culture medi fter io-processing not only supplies nutrients to the plnts, ut lso improve the physicl, chemicl nd iologicl properties. For improving conditions of plnting sustrte could e used from composting process for different prticle sizes. This reserch ws crried out using completely rndomized design with two tretments nd three replictions. Dte-plm wstes crushed y comine nd then they were sieved in two sizes with mesh (sieve). The tretments were prticle of dte plm wstes with two sizes including -5 nd 1- mm. The incution time for composting process ws 18 dys. Smpling ws done once every two weeks. Temperture of smples ws mesured once every week during the period of composting. The results showed tht orgnic cron content in dte plm wstes reduced in oth prticle size with incresing in incution time nd hd significnt differences (p<.5). With incresing in incution time, totl nitrogen incresed nd t the most smples, in the prticle size of 1- mm ws more thn -5 mm. With incresing in incution time, C/N rtio reduced in oth sizes. KEY WORDS: Dte plm wste, Composting, Prticle Size, C/N rtio, Temperture 1. INTRODUCTION: Use of suitle growing medi or sustrtes is essentil for production of qulifying horticulturl crops. It hs directly ffects on the development nd lter mintennce of the extensive functionl rooting system. A good growing medium would provides sufficient nchorge or support to the plnt, serves s reservoir for nutrients nd wter, llow oxygen diffusion to the roots nd permit gseous exchnge etween the roots nd tmosphere outside the root sustrte. The origin of dte plm tree is in the south of Irn nd Irq, however, tody it is cultivted in mny res of world. It is estimted tht out 3% of griculturl lnds in the world is under dte plm cultivtion. Currently, pproprite mngement nd optimized procedure is not in use for this mteril (Borji et l, 1). In composting, the industry needs to nlyze the physicl, chemicl nd iologicl properties of compost to determine the completing degree of composting process with ssessing the different chnges in physicochemicl nd iologicl properties of rw compost (Levnon nd Plud, 2). During the composting process, microorgnisms trnsform orgnic rw mterils into compost y reking them down to simple compounds nd reforming them into new complex compounds

2 The 1 th Interntionl nd The 4 th Ntionl Congress on (Mohmmd et l., 8). Among these, the properties cn point to C/N rtio, CEC, ph, porosity, ulk density nd slinity of compost. Immture compost hs hi C/N rtio tht cn cuse deficiency of N in plnt. The flling vlue of C/N rtio is sign of fermenttion nd the performnce of the composting process during mintennce period. Microorgnisms supply their primry energy from C of compost, while the N of compost is used y microorgnisms to develop their colonies for reking down the orgnic mtters. Microorgnisms use the /1 rtio of C/N. If this rtio increses up to, the rte of compost rekdown will decrese. Of course, this rtio decreses in the composting process for long period of time. As such, ttention must e pid to this rtio, ecuse the extr N chnges to NH4 + when it decreses elow 25, (Brrington et l., 2). Nitrogen is used for the synthesis of cellulr mteril, mino cids, nd proteins nd is continuously recycled throu the cellulr mteril of the micro-orgnisms. Any nitrogen tht is incorported into the cells ecomes ville gin when the microorgnism dies. Becuse lrge prt of the cron is continuously relesed while the mjority of the nitrogen is recycled, the C: N rtio decreses over the composting period. If, however, the system experiences lrge nitrogen losses, the C: N rtio cn increse (Grves et l.). A convenient nd meningful compost prmeter to monitor is temperture. Temperture is n indictor of microil ctivity. By recording tempertures dily, norml pttern of temperture development cn e estlished. Devition from the norml pttern of temperture increse indictes slowing of or unexpected chnge in microil ctivity. The temperture should egin to rise stedily s the microil popultion egins to develop. If it does not egin to rise within the first severl dys, djustments must e mde in the compost mix. 2. MATERIALS AND METHODS: This reserch ws crried out in reserch greenhouse of Islmic Azd University, khorsgn rnch, using completely rndomized design with two tretments nd tree replictions. Dte-plm wstes crushed y comine nd then they were sieved in two sizes with mesh (sieve). The tretments were prticle of dte plm wstes with two sizes including -5 nd 1- mm. The incution time for composting process ws 18 dys. The moisture content of wstes t eginning of composting period incresed to 7-6 percent (w/w). They were kept in the 1 m 3 plstic gs for controlling the moisture nd temperture. Some mounts of N nd P fertilizers were dded to them s fermenttion strter, nd these gs were plced in hot (25 to C) condition. For respirtion, some ir holes were mde on the gs. Every week, these mterils were mixed together nd put into the gs gin nd their moisture ws djusted to 65%. Every two weeks smples took up from tretments nd nlyzed for determintion of C/N rtio. Orgnic C ws determined ccording to the comustion method (McKegue, 1976). Totl nitrogen ws determined using kjedhl, nd then C/N rtio ws clculted. Dt were nlyzed using Sttisticl Progrm for Socil Sciences (SPSS). 3. RESULTS AND DISCUSSION: The effect of composting period on orgnic mtter percentge in tretments illustrted in fig 1. The results showed tht orgnic cron content in dte plm wstes reduced in oth prticle size with incresing in incution time nd hd significnt differences (p<.5) so the tretment with 1- mm size hd hve more orgnic cron content in every time. Cron is used oth s source of energy nd for growth of microes. In eroic decomposition, prt of the cron is relesed s CO2 while the rest is comined with nitrogen for microil growth.

3 The 1 th Interntionl nd The 4 th Ntionl Congress on As result, the cron content of compost pile is continuously decresing (Grves et l.). 6 5 cde f efg c cd h g-j g-j cd def j f g-j i h g-j l k kl kl kl k OC (%) 1 Strt Time (dy) Figure1. Chnges in orgnic cron of the composting with different size of dte- plm wstes. Fig. 2, showed tht with incresing composting time, totl nitrogen incresed nd t the most smples, mount of totl nitrogen in the prticle size of 1- mm were more thn -5 mm. Nitrogen is used for the synthesis of cellulr mteril, mino cids, nd proteins nd is continuously recycled throu the cellulr mteril of the micro-orgnisms (Grves et l.). 2.5 TN (%) cde e de cde g fg fg fg fg h e de cde cde cd f e cde cd c.5. Strt Time (dy) Figure2. Chnges in totl nitrogen of the composting with different size of dte- plm wstes. Fig. 3, showed tht with incresing nd t the most time of this study, C/N rtio in the prticle composting time, C/N reduced in oth size of -5 mm ws more thn 1- mm. Any nitrogen tht is incorported into the cells ecomes ville gin when the micro-orgnism dies. Becuse lrge prt of the cron is continuously relesed while the mjority of the nitrogen is recycled, the C: N rtio decreses over the composting period. If, however, the system experiences lrge nitrogen losses, the C: N rtio cn increse (Grves et l.).

4 45 The 1 th Interntionl nd The 4 th Ntionl Congress on C/N c cd cde ef de fg fg cd h jk jk lm i jk jkl klm m Strt Time (dy) Figure3. Chnges in C/N rtio of the composting with different size of dte- plm wstes. The temperture chnges in the wstes mss during the composting process of re shown in Figure 4. The temperture of wstes mss ws decresed with incresing in incution time. The results showed mximum temperture (49 o C) for prticle size of 1-mm t 14 dys. Finlly, the temperture of mss decresed nd stilized t 18 o C fter 161 dys, therefore composting process y micro orgnism in this time ws finished nd dte plm wstes were mturted. The temperture pttern shows the microil ctivity nd the occurrence of the composting process (Bernl et l. 9). The optimum temperture rnge for composting is 65 o C (De Bertoldi et l. 1983); tempertures ove 55 o C re required to kill pthogenic microorgnisms mm 1-mm Temperture( C ) Dys of composting Figure 4.Temperture chnges during composting process in different size of dte- plm wstes.

5 4. CONCLUSIONS: The 1 th Interntionl nd The 4 th Ntionl Congress on The results showed tht orgnic cron content in dte plm wstes reduced in oth prticle size with incresing in incution time nd hd significnt differences (p<.5). With incresing in incution time, totl nitrogen incresed nd t the most smples, in the prticle size of 1- mm ws more thn -5 mm. With incresing in incution time, C/N rtio reduced in oth sizes. REFERENCES 1. Brrington S, Choiniere D, Trigui M, Knit W (2). Effect of cron source on compost nitrogen nd cron losses. Bioresour. Technol. 83: Bernl, M.P., J.A. Alurquerque nd R. Mor. 9. Composting of niml mnures nd chemicl criteri for compost mturity ssessment. A review. Bioresour. Technol. 1: Borji H, Mohmmdi Ghehsreh A, Jfrpour M. 1. Effects of the Sustrte on Tomto in Soilless Culture. Reserch Journl of griculture nd Biologicl Sciences, 6(6): De Bertoldi, M., G. Vllini nd A Per The iology of composting: review. Wste Mnge. Res. 1: Grves R E, Httemer Gwendolyn M, Stettler D,. Composting in Prt 637: Environmentl Engineering Ntionl Engineering Hndook. United Sttes Deprtment of Agriculture, Nturl Resources Conservtion Service. 6. Levnon D, Plud D (2). Chemicl, physicl nd iologicl criteri for mturity in composts for orgnic frming. Compost. Sci. Util. 1(4): McKegue, J.A., Mnul on soil smpling nd methods of nlysis. Soil Reserch Institute of Cnd.