The word composting refers to the process of decay that

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1 Ancient Wisdom Meets Modern Science Studies & Advnces in Composting Technology y Pul Hepperly, Ph.D. & Christine Ziegler Ulsh The word composting refers to the process of decy tht produces stle, high-cron humus from plnt nd niml residues or wstes. The composting process trnsforms these wste mterils into nutrient-rich, soil-like mteril tht cn e used to improve grden nd frm soils round the world. Compost forms the foundtion of modern orgnic frming, which cn e trced ck to the work of Sir Alert Howrd (see sider, pge 17), nd its importnce in sustinle nd orgnic models of griculture cn hrdly e overstted. 38 cm 76 cm Flexile Air Intke Tue 76 cm Steel Well Csing Lysimeter Body with intct soil core Steel Bse Plte 45 cm Drin Are 6 mm Drin Holes 7.6 cm Treded Nipple PVC Cp Connecting Tue Wter Meter Box Lechte 21 Liter Jug Flexile Lechte Suction Tue 9 Degree Bulkhed Fittings Figure 1. Digrm of n intct-core lysimeter instlled in field under the crop root zone. The lysimeter s ody cylinder ws driven into the ground y force to mintin n undistured soil profile within the cylinder. The cylinder nd core were then rised out of the ground, nd the steel se plte ws welded into plce to collect ny wter tht rn through the core. THE COMPOST UTILIZATION TRIAL To scientificlly ssess the vlue of compost in frming, the Rodle Institute ( nonprofit orgniztion strted y J. I. Rodle) initited decde-long study compring the use of compost, rw mnure nd synthetic chemicl fertilizer for the production of, corn nd vegetle rottion. This experiment ws strted with collortive review y United Sttes Deprtment of Agriculture reserch scientists. Begun in 1993, the Compost Utiliztion Tril (CUT) ws designed to mesure the long-term effects of these fertiliztion techniques on soil nd wter qulity. This study confirmed the superiority of compost s compred to rw mnure or synthetic chemicl fertilizers over long term s mens to improve soil helth nd reduce wter contmintion. Bsed on the findings, the Pennsylvni Deprtment of Environmentl Protection funded the study of compost mendment mix to further increse the nutrient retention in composts, oth during the composting process nd in field ppliction. Reserchers strted designing the CUT study in 1991 nd then egn plnting its rottions in the field in The experiment tested seven fertility tretments (five types of compost, long with rw diry mnure nd synthetic chemicl fertilizer) in three-yer rottion of, corn nd vegetle (originlly green peppers; lter, pottoes), mintined continuously through 22 (see Tle 1). Yields nd nutritionl content were mesured for ll the crops in the rottions, nd cover crops were nlyzed for iomss nd tissue nutrients. Field soils were tested nnully for fertility, nd soil wter ws recovered in intct-core lysimeters tht were instlled elow the crop root zone to mesure the mounts of nitrtes nd phosphtes tht were eing lost from the system to the ground wter (see Figure 1).

2 2th Century Compost The Birth of Modern Orgnic Agriculture y Pul Hepperly & Christine Ziegler Ulsh Compost hppens, nd hs een hppening nonstop throughout history. It is referenced repetedly in the Old Testment. Sir Alert Howrd ( ), the fther of modern orgnic frming, found tht ncient composting prctices were center to mintining soil fertility nd lnce, especilly in the tropics. These prctices hve een developed nd refined during the lst 6, yers nd hve stood the test of time. Sir Alert Howrd ws trined s conventionl gronomist in Gret Britin nd served mny yers in the British Overses Service ddressing griculturl issues in tropicl regions. During n erly ssignment in the British West Indies, he discovered tht fertiliztion prctices tht worked well in temperte climtes were much less effective in the tropics. This ws due in prt to the predominnce of cid soils in the humid tropics tht re mde even more inhospitle with use of cid-generting mmonited fertilizer. Compost, unlike mmonited fertilizer, is neutrl or slightly lkline nd hs uffering effect on cid-relted toxicity (such s luminum nd mngnese toxicity). Working with these cid soils, Howrd hd n epiphny tht led to the development of modern orgnic griculturl theory nd prctice. He noticed tht nture nd ntive griculturl prctices recycled plnt mterils to conserve nd increse soil fertility. After his time in the British West Indies, Howrd worked from 195 to 1933 in Indi, where he ecme reporter, supporter nd developer of compost technology. In contrst to Justus Lieig, who promoted fertiliztion pproch to plnt nutrition, Howrd chmpioned ig-picture view of plnt production, recognizing the importnce of soil orgnic mtter in meeting ll the nutritionl needs of the plnt. MODERN COMPOSTING Howrd s experiments demonstrted tht compost generted higher plnt productivity thn either fertilizer or rw mnure. In Howrd s clssic tretise on orgnic griculture, An Agriculturl Testment (194), the gretest single topic he covered ws the Indore composting method, identified, studied, nd dpted from prctices in Indore, Indi. The Indore composting method fetures lyering of diverse mterils to promote n optimized cron-nitrogen rtio for optiml composting. The lyered mterils re periodiclly mixed to erte them nd stimulte helthy eroic decy (neroic decy cn generte toxic yproducts, see Let Your Compost Brethe in this issue). This method reduces the volume of the initil mterils y 6 percent or more nd cretes finished humus-rich product tht is idel for use in the field s soil fertility mendment. This finl product is often referred s lck gold J. I. Rodle clled it py dirt. The Indore system, s pplied in compost windrows, hs evolved to ecome the primry pproch of most modern municipl compost opertions. And lthough the technology to turn the compost windrows hs dvnced impressively over the yers, the compost recipe hs remined lrgely unchnged. J. I. Rodle, the pioneer of Americn orgnic griculture nd grdening, ws instrumentl in populrizing the use of composting for orgnic food production. In 1942, Rodle selected Howrd s the first scientific editor for his lndmrk Orgnic Frming nd Grdening mgzine. Like Howrd, Rodle considered compost to e the minsty of the orgnic method, s explined in his ook Py Dirt (1945). Sir Alert Howrd s An Agriculturl Testment is ville from the Acres U.S.A. ookstore. INITIAL FINDINGS Crop yields were generlly similr mong ll tretments, indicting tht compost or rw mnure generted little or no production penlty nd cn provide the sme yields s conventionl fertilizer (see Figure 2). Moreover, t the lter prt of the experiment nd corn yields tended to e higher in oth yield nd protein content when compost ws used. Note tht over time, nd corn yields from oth compost tretments (roiler litter nd diry mnure se) incresed from 9 to 25 percent, while yields from conventionl fertilizer incresed y only 1 to 8 percent over the experimentl period. This indictes tht, in longer tril, compost would proly continue to ccumulte enefits over conventionl synthetic fertilizer pplictions. Overppliction of crop nutrients is growing concern s wter pollution nd helth issues increse. Crop nutrients cn e overpplied in ny frming system, conventionl or orgnic, unless frmers tke cre to fine-tune their nutrient pplictions to meet (nd not exceed) the needs of their crops. In CUT, composts were found to reduce nitrte leching into the soil wter y over 5 percent compred to rw mnure or fertilizer ppliction (see Figure 3). No significnt differences in phosphte leching were found mong tretments. Becuse nutrient mendment ppliction rtes were sed on estimted solule nitrogen content, the composts were pplied t much higher rtes thn the rw mnure or synthetic fertilizer. Contrry to conventionl thinking, pplictions of compost cn oth increse soil nutrient levels nd reduce leching s compred to recommended uses of either rw mnure or conventionl synthetic fertilizer. Soil cron levels incresed from 1.97 percent to 2.5 percent in the diry mnure lef compost tretment, representing n increse of.53 percent in the top

3 Entry Point 1 Entry Point 2 Entry Point MAIZE OATS; sorghum SPINACH; MAIZE sorghum; sorghum; crimson clover MAIZE crimson clover; rye red clover red clover; rye red clover hiry vetch red clover; rye hiry vetch; rye hiry vetch hiry vetch; hiry vetch hiry vetch hiry vetch; hiry vetch; hiry vetch pottoes; Tle 1. Compost Utiliztion Tril crop rottions from Entry points 1, 2 nd 3 occurred in ech yer for ech of the seven fertiliztion tretments. Cpitlized nmes in old indicte crops tht were hrvested tht yer. The rottion ws chnged in 1995 to include hiry vetch s legume green mnure fter, nd in 1996 rye cover crop ws dded fter mize. Finlly, in 22, pottoes replced peppers in the vegetle phse of the rottion. crop yield (kg/h) Crop Yields From Different Tretments of the Compost Utilitztion Tril ( ) Pre-Vetch Period Broiler Litter/Lef Compost Diry Mnure/Lef Compost Rw Diry Mnure Conventionl Fertilizer Vetch Period Nitrte-N leched (kg/h) Nitrte-nitrogen Leched from Fields Enriched with Compost, Mnure or Fertilizer, y Yer Broiler Litter/Lef Compost Diry Mnure/Lef Compost Rw Diry Mnure Conventionl Fertilizer 1 Corn Grin Whet Grin Corn Grin Whet Grin Figure 2. Crop yields (dry weight) for the three csh crops grown under different fertiliztion tretments, ssessed oth efore nd fter hiry vetch ws dded to the crop rottion. Tretments in crop grouping with the sme letter re not significntly different t the P <.5 level. Figure 3. Nitrte-N leched from fields treted with compost, mnure nd synthetic fertilizer. 9 inches of the soil profile (see Figure 4). Given tht the top 9 inches of soil dds up to out 3,, pounds per cre, this increse in orgnic mtter dds up to 15,9 extr pounds of cron per cre over the life of the study, with wter-holding cpcity of 636, pounds per cre (n increse of 26.9 percent over the 59,1 pounds of cron per cre found in the soil t the strt of the tril). Clculted nnully, compost ppliction incresed soil cron y up to 2, pounds/cre/yer, while mnure ppliction generted n increse of less thn 2 pounds/cre/yer, nd synthetic fertilizer tretment did not improve soil cron levels t ll. This point is importnt ecuse other Rodle Institute reserch hs shown tht, when griculturl prctices rise levels of soil orgnic mtter, corn nd soyen yields cn increse y up to 3 to 4 percent in drought yers, compred with unimproved soils. Thus, compost-sed improvements in soil orgnic mtter levels cn go long wy to help protect crops ginst drought dmge. The progrmmtic increse of soil orgnic mtter cn e seen s n effective wy to drought proof crop production systems under rinfll nd n effective to reduce wy demnd of irrigted crops. Compost pplictions lso incresed soil nitrogen levels (see Figure 5). Under our field conditions, every 2 percent increse in reltive soil cron levels hs coincided with 1 percent reltive in soil nitrogen content. The uild-up of soil nitrogen reserves vi compost incorportion reduces the need for ppliction of nitrogen mendments over time. This effect cnnot e duplicted y chemicl fertilizers, which hve tendency to reduce soil nitrogen reserves nd, s such, require repeted nnul ppliction. The

4 % soil nitrogen Chnges in Soil Cron from 1992 to 21 For Different Fertiliztion Tretments in the Compost Utiliztion Tril Broiler Litter/Lef Compost Diry Mnure/Lef Compost Rw Diry Mnure Conventionl Fertilizer % totl nitrogen Chnges in Soil Nitrogen from 1992 to 21 for Different Fertiliztion Tretments in the Compost Utiliztion Tril Broiler Litter/Lef Compost Diry Mnure/Lef Compost Rw Diry Mnure Conventionl Fertilizer c Figure 4. Soil cron (-2 cm) chnges y tretments from 1992 to 21. BLLC = roiler litter lef compost; CNV = conventionl minerl fertilizer; DMLC = diry mnure lef compost; RDM = rw diry mnure. Figure 5. Soil nitrogen (-2 cm) chnges in 1992 nd 21 s influenced y nutrient sources. Different lower-cse letters ove rs indicte significnce (P =.5) etween tretment. NSD = not significntly different t P <.5. BLLC = roiler litter lef compost; CNV = conventionl minerl fertilizer; DMLC = diry mnure lef compost; RDM = rw diry mnure. use of compost dds to the soil nitrogen nk ccount, which over time llows the frmer to live off the interest of this ccount. In the cse of synthetic fertilizer, s much or more nutrient input is needed ech yer, nd the soil nk levels ctully decreses. Becuse compost is certified orgnic production prctice, frmers cn use it to meet crop nutrient needs during orgnic trnsition, eventully llowing them to cpture the economic enefits of premiums, which run nywhere from 4 to 267 percent for grins nd hve verged out 15 percent for the lst four yers ccording to Orgnic Price Index dt for corn. Some frmers hve een reluctnt to try mking compost t the frm scle due to the potentil costs of dded equipment nd/or time tht compost turning entils. However, with some plnning nd it of prctice, lrge quntities of compost cn e turned with regulr ucket loder. Before the Rodle Institute developed its compost turner (see elow), frm workers developed system to turn 15 footlong windrow of compost with ucket loder in little under two hours. Use of existing equipment nd mking compost in the winter when other opertions require less time cn llow frmers to try their hnds t composting without mking n initil cpitl outly. For frmers who find composting to e good fit for their opertion, Jeff Moyer (frm mnger for the Rodle Institute) worked with neighoring frmer nd metl worker to develop homemde compost turner, constructed from prts of n old dump truck nd other cstoff equipment. Informtion out the design nd ssemly of this turner cn e found online t fetures/84/compost/slideshow/turner1. shtml mking efficient nd resonly inexpensive compost turning possile for the innovtive frmer. REDUCING NUTRIENT LOSSES Soil ggregtion (clumping of soil prticles) hs een pinpointed s key indictor of soil qulity nd structurl integrity, helping the soil etter retin wter, ir nd nutrients. A soil s tendency to ggregte is primrily function of its orgnic mtter content: The higher soil s orgnic mtter levels, the more likely it is to ggregte. Dr. Frnk Stevenson, soil chemistry professor t the University of Illinois, determined tht n effective wy to stilize orgnic mtter in soil is to foster its comintion with cly. Becuse orgnic mtter prticles nd cly prticles re oth negtively chrged, Stevenson lso found tht positively chrged prticle, such s clcium, iron nd luminum, re essentil to onding the orgnic mtter nd cly, creting n ggregte. The positively chrged clcium ions serve s ionic glue to ctlyze ggregtion of ll the prticles into soil clumps. Soil ggregtes form empty spces (pores) etween them, which improves wter nd ir penetrtion. In ddition, s hollow spheres, their interior spces re ldders tht fill with wter, ir nd nutrients, essentil to support virnt crops (see Figure 6). DEP COMPOST RESEARCH Dn Desmond, technology director for the Pennsylvni Deprtment of Environmentl Protection, chllenged the Rodle Institute to develop technology tht would further improve the nutrientretention properties of mnure-sed composts, oth in the pile nd on the field. DEP s interest in composting is driven y the need to reduce ppliction of rw mnure on frm fields, prticulrly in Lncster County, where rw mnure pplictions hve een proven primry cuse of nutrient pollution in the Chespeke By nd surrounding wtershed. The Rodle Institute thus developed study to mesure the mounts of crop nutrients tht lech off compost piles during the composting process, nd then to pply the composts to the field in conjunction with rw mnure nd chemicl fertilizer to compre soil nutrient

5 Qurtz Grin Bcteri Qurtz Grin Wter AIR cly prticle orgnic mtter cly prticle AIR Qurtz Grin Figure 6. Cly nd orgnic mtter ond with the id of clcium, iron nd/or luminum to crete stle soil ggregte (clump) tht contins pore spces to hold wter, ir nd nutrients to support plnt growth nd soil microil life. Figure 7. Compost pd with collection system. The inset picture shows the concrete pd on which the compost piles were constructed nd ged. The drin grids in the middle nd front of the pd collect wter tht runs through the compost pile nd send it into septic tnk (the ottom picture, one tnk for ech pd) for lter nlysis. run-off nd crop yields. As prt of this tril, reserchers tested three different compost formultions: 1. Rw mnure llowed to ge y itself (unmixed with other mterils); 2. A stndrd lef-mnure compost mix (three prts leves, one prt mnure, y volume); 3. An mended compost mix tht incorported cly, clcium, nd humic cid (n stle orgnic cron sed mteril). The recipe for the mended compost, s mixed for the study, incorported seven uckets (1 cuic yrd ech) of leves with two uckets of mnure, one ucket of cly (tken from the frm s susoil), 45 pounds of clcium sulfte, nd 55 pounds of humic cid (purchsed from Terrvit Inc., SP85). All the compost tretments were piled nd ged on eveled concrete sls with drin grid tht fed into n underground septic tnk for wter collection (see Figure 7). The piles were monitored for temperture (dily), mteril nutrient content (t the strt nd end of the composting cycle), nd nutrient nd cteril content of the wter tht leched through the pile (collected from the tnk severl times throughout the composting cycle). Figure 8. Three of the roiler litter compost piles on the composting pds. The pile on the left is the mended compost mix, the middle pile is roiler litter lone, nd the right pile is the stndrd mnure-lef compost mix. Note tht the two compost mixes hve reduced in volume compred to the mnure lone (ll piles were the sme size t the strt of the composting cycle). Volume reduction of compost piles is good indiction of effective composting. Two rounds of compost were generted, one sed on poultry mnure tht ws mixed nd mtured from My to Octoer 25, nd nother sed on diry mnure tht ws mde from Octoer 25 to April 26 (see Figure 8). During ech round, ech of the three compost tretments (mnure lone, mnure-lef compost, nd mended mnure-lef compost) ws replicted twice. In order to reduce nitrogen nd cron loss to the ir, the mixed compost piles were specificlly lyered with leves on the ottom nd top nd the mnure sndwiched in the middle (with the mendment mix in those tretments) nd llowed to stnd, unmixed, for two weeks efore the first turning. The gol of the lyering ws to llow the leves to cpture ny nitrogen tht might off-gs from the mnure during tht initil period. Our gol ws to turn the piles s little s possile, to retin s much nitrogen nd cron s possile in the pile, nd to llow the ggregtion process nd fungl development to proceed unhindered. The turning schedule ws sed on the temperture cycle of the pile: When tempertures dropped elow the strting temperture of the previous cycle, the pile would then e turned gin (see Figure 9). Following these guidelines, we turned the piles totl of three times over the six-month composting cycle.

6 Broiler Litter-Bsed Compost Pile Tempertures through the Composting Cycle (My to Oct. 25) degrees C first turning June 1, 25 Broiler Mnure Leves-Broiler Mnure second turning June 4, 25 Leves-Broiler Mnure-Amendments dys from strt third turning Septemer 14, 25 Mnure lone Amended Compost Stndrd Compost Stndrd Compost Mnure lone Amended Compost Figure 9. Temperture fluctutes in roiler-litter compost tretments. Arrows indicte points t which the piles were turned. Tempertures in the mnure lone never chnged much over the cycle, indicting limited eroic microil ctivity. The temperture curve suggests tht the mended compost cooled nd finished little more quickly thn the stndrd compost mix. Figure 11. Compost lechte collected from tnks elow the compost piles. Mnure lone leched mny sediments nd nutrients, while the stndrd compost leched fewer, nd the mended compost leched lest. Mnure lone Leves/Mnure Leves/Mnure/ Amendments Figure 1. Surfce leching of pile nutrients nd sediments fter hevy rin. The unmixed mnure pile leched gresy, smelly colloidl liquid (left), while the stndrd compost pile leched only few odorless sediments (center), nd the mended compost leched lmost no wter t ll. RECENT FINDINGS Within one week fter piling, the mended compost emitted no mmoni or sulfur odors, while the stndrd compost mix required three to four weeks to eliminte the smells. The mnures, when piled lone, never lost their odor (prticulrly the roiler litter, which still smelled yer lter). As shrewd frmer from New York Stte noted, If it smells, you re losing your nutrients. Thus, odor reduction is not merely n esthetic concern or neighorly courtesy; it is essentil to improve the nutrient retention nd vlue of compost. Nutrient losses were lso esy to ssess visully. After prticulrly hevy rin ner the end of the poultry mnure composting cycle, the pile of unmixed mnure leched gresy colloid mteril tht looked nd smelled d. The stndrd compost leched little wter off its edges, ut the liquid contined only little sediment from the pile. At the sme time, the mended compost mix leched lmost no wter t ll (see Figure 1). Extending the down-home logic of our New York Stte neighor if your pile is weeping, you re losing nutrients. Differences could lso e seen in the lechte collected from the tnks elow the pds. Lechte drwn from the unmixed mnure piles ws lck nd thick like motor-oil, while the stndrd compost leched liquid the color of drk te, nd the mended compost leched liquid tht more resemled light te (see Figure 11). Lechte drwn from the mended composts contined much less nitrogen nd phosphorus thn tht drwn from the stndrd compost or mnure lone (see Figure 12). (The dt, while showing cler trend, were not significnt due to repliction constrints enforced y the numer of compost pds.) In ddition, oth mended nd stndrd composts eliminted E. coli in their lechte, ut the mended compost did so twice s quickly s the stndrd compost (dt ville upon request). The rw mnure continued to shed E. coli in its lechte throughout the compost cycle (nd presumly eyond). Aggregte formtion ecme evident in the mended composts within seven to 2 dys, s compred to 6 to 8 dys for stndrd compost. In contrst, even fter yer, the poultry mnure lone ws still wet, gooey nd smelly, showing little sign of ny eroic composting. The diry mnure lone composted somewht etter due to the presence of edding (cron-rich mterils) nd digestive cteri inherent in the mnure. However, even fter hlf-yer of composting, little

7 Totl Nitrogen, Phosphorus & Slts Leched from Poultry Litter Composts & Diry Mnure Composts totl N (NO3 + NH4) g ortho-p g Corn Grin Figure 12. Nutrients nd slts leched from poultry mnure composts (green) nd diry mnure composts (rown) throughout the composting cycle. ggregtion hd occurred in the diry mnure lone, nd the piles still smelled fintly. The finl nutrient nlyses of ech of the compost reveled tht the mended composts most closely chieved 2:1:2 N:P:K rtio, most idel to support plnt growth nd the sis for most chemicl fertilizer mixtures (see Figure 13). The rw mnures tended to e high in phosphorus nd potssium reltive to nitrogen, sitution tht could led to overppliction of these nutrients to meet crop s nitrogen needs. Over time, these overpplictions would likely led to nutrient leching from the soil into oth ground nd surfce wters. Soil testing dt confirm tht, y mid-seson, soils tht received rw poultry mnure Poultry Alone (9/5) Poultry-Leves (9/5) Poultry-Leves-Amend (9/5) Diry Alone (3/6) Diry-Leves (3/6) Diry-Leves-Amend (3/6) Whet Grin Solule slts kg hd significntly higher nitrogen c o n c e n t r t i o n s thn the other tretments. Nutrient leching dt from field pplictions of the compost were generlly inconclusive, ut corn yield dt showed tht, in tht single yer, conventionl fertilizers supported higher yields thn the mended diry mnure compost. All the other composts nd mnures supported yields tht were not significntly different from either the conventionl fertilizer or the mended diry compost. These dt indicte tht we my hve overestimted the nitrogen vilility of the mended diry compost, ttesting to its ility to retin nutrients. However, s dt from the Compost Utiliztion Tril showed, composts were le to uild up soil orgnic mtter nd nutrient content to support yields equl or etter thn conventionl fertilizer or rw mnure when pplied over few yers. As such, future compost reserch should e plnned to cover t lest five field sesons to show more relistic picture of soil fertility nd crop yields cross tretments. CONCLUSIONS The ncient prctice of composting is n idel solution to modern griculture s nutrient wste issues. Compost pplictions improve soil orgnic mtter content, nitrogen content, nd its ility to support crops under drought conditions, while rw mnure nd chemicl fertilizer do not offer these long-term enefits. Multi-yer reserch shows tht compost lso reduces nitrogen losses to wter systems when compred to rw mnure or chemicl fertilizer. Wht s more, for one of the first times in the history of composting, reserch hs found wy to ctully improve the sic chemistry of the composting process, eyond the lnce of greens, rowns nd moisture. With the ddition of the cly-clcium-humic cid mendment, we hve found tht soil ggregtion processes cn e expedited s prt of the composting process, nd these ggregtes cn increse compost s positive impct on soil fertility nd structure. This simple mendment mixture demonstrted mrked ility to (1) ccelerte the compost process, (2) gretly reduce odors tht coincide with nitrogen nd sulfur nutrient losses, (3) provide fster nd more durle ggregtion of the recycled compost mterils nd (4) more quickly eliminte E. coli leching in the composting process. Composting represents multiple enefits tht frmers nd griculturl professionls re just eginning to fully Finl Nutrient Anlysis of Poultry Mnure Composts (Octoer 25) Finl Nutrient Anlysis of Diry Mnure Composts (April 26) 7 5 Percent Dry Weight (%) Corn Grin Totl Nitrogen (N) Orgnic Nitrogen Phosphorus (P2O5) Potssium (K2O) Whet Grin Percent Dry Weight (%) Totl Nitrogen (N) Orgnic Nitrogen Phosphorus (P2O5) Potssium (K2O) Whet Grin Poultry Mnure Alone Poultry Mnure/Leves Poultry Mnure/Leves/Amendments Diry Mnure Alone Diry Mnure/Leves Diry Mnure/Leves/Amendments Figure 13. Nutrient rtios for the finished poultry mnure composts nd diry mnure composts.

8 pprecite. By expnding nd improving compost production nd use, the griculturl community increses its opportunities to recycle wste mterils (prticulrly mnure), improve soil helth nd productivity for genertions to come, nd lso improve tmospheric helth through the cpture of greenhouse gses (cron nd nitrogen) in the soil. The gretest power of compost production nd use lies in the fct tht, s frmers dopt these prctices to improve their own ottom line, they lso constructively impct other people nd the plnet s whole y producing helthier food from helthier soil, clening up wterwys, nd reducing glol wrming. Cron credit progrms could e n excellent wy to encourge frmers to strt mking nd using compost. These progrms cn ct s n ffirmtive crrot to the stick of incresingly strict griculturl wter pollution regultions, which cn lso e met through compost production nd use. The Rodle Institute will continue to work with the Pennsylvni Deprtment of Environmentl Protection nd Deprtment of Agriculture to develop compost production models tht will rewrd frmers for their ility to positively impct the environment nd humn helth through this simple, ncient, powerful prctice. Dr. Pul Hepperly serves s the Reserch nd Trining Mnger t the Rodle Institute. He grew up on fmily frm in Illinois nd holds Ph.D. in plnt pthology, n M.S. in gronomy nd B.S. in psychology from the University of Illinois t Chmpign-Urn. He hs worked for the USDA Agriculturl Reserch Service, in cdemi, nd for numer of privte seed compnies, including Asgrow, Pioneer nd DeKl. He hs overseen reserch in Hwii, Iow, Puerto Rico nd Chile, nd investigted such diverse crops s soyens, corn, sorghum, sunflowers, ginger nd ppy. Christine Ziegler Ulsh is reserch technicin t the Rodle Institute She holds B.A. in Biology from Smith College nd M.S. in Forestry t the University of Msschusetts. Her creer hs included reserch t the university nd with the USDA Forest Service, nturl foods retil sles, dministrtion nd frm work. More informtion t Acres U.S.A. is the ntionl journl of sustinle griculture, stnding virtully lone with rel trck record over 35 yers of continuous puliction. Esh issue is pcked full of informtion eco-consultnts regulrly chrge top dollr for. You ll e kept up-to-dte on ll of the news tht ffects griculture regultions, discoveries, reserch updtes, orgnic certifiction issues, nd more. To suscrie, cll (toll-free in the U.S. & Cnd) / fx P.O. Box / Austin, TX 7879 info@cresus.com Or suscrie online t: