MR405: Response of Young Black Spruce (Picea mariana (Mill.) B.S.P.) to a Mixture of Wood Ash and Secondary Papermill Sludge

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1 The University of Mine Misellneous Reports Mine Agriulturl nd Forest Experiment Sttion -997 MR45: Response of Young Blk Sprue (Pie mrin (Mill.) B.S.P.) to Mixture of Wood Ash nd Seondry Ppermill Sludge Roert K. Sheprd Follow this nd dditionl works t: Reommended Cittion Sheprd, R.K Response of young lk sprue (Pie mrin (Mill.) B.S.P.) to mixture of wood sh nd seondry ppermill sludge. Mine Agriulturl nd Forest Experiment Sttion Misellneous Report 45. This Report is rought to you for free nd open ess y DigitlCommons@UMine. It hs een epted for inlusion in Misellneous Reports y n uthorized dministrtor of DigitlCommons@UMine. For more informtion, plese ontt um.lirry.tehnil.servies@mine.edu.

2 ISSN 7-56 CFRU Progress Report 34 Response of Young Blk Sprue (Pie mrin (Mill.) B.S.P.) to Mixture of Wood Ash nd Seondry Ppermill Sludge Roert K. Sheprd Misellneous Report 45 Deemer 997

3 CFRU Progress Report 34 Response of Young Blk Sprue (Pie mrin (Mill.) B.S.P.) to Mixture of Wood Ash nd Seondry Ppermill Sludge Roert K. Sheprd Professor Deprtment of Forest Mngement College of Nturl Sienes, Forestry nd Agriulture University of Mine Orono, Mine Misellneous Report 45 Deemer 997

4 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 INTRODUCTION A study to exmine the effets of omintion of wood sh nd seondry ppermill sludge pplied to lerut plnted to lk sprue ws initited in 987 with the oopertion of Gret Northern Pper. Ojetives of the study were to ssess the effets of the residuls on () seedling growth, () seedling folir element onentrtions, nd (3) hemil properties of the forest floor nd minerl soil. This report emphsizes growth results for 99 through 995 nd folir element results through 994. However, some results otined prior to 99 re presented, primrily s kground informtion. Some informtion on soil ph is presented in the disussion of folir element onentrtions, due to the importne of ph in regulting element vilility nd uptke. For those not requiring the degree of detil inluded in this report, summry is presented t the end. PROCEDURES The study ws estlished in lerut plnted to - lk sprue (Pie mrin (Mill.) B.S.P.) seedlings in the spring of 986. The seedlings were grown in pper ontiners y Gret Northern Pper. Prior to hrvest, the site ws oupied y mixed hrdwood stnd, with white irh (Betul ppyrifer Mrsh.), tremling spen (Populus tremuloides Mihx.), igtooth spen (Populus grndidentt Mihx.), nd red mple (Aer rurum L.) eing the dominnt speies. There were osionl red sprue (Pie ruens Srg.) nd estern hemlok (Tsug ndensis (L.) Crr.) sttered throughout the stnd. The soil is Hermon very stony, sndy lom. This soil is orse textured, rnges from well drined to somewht exessively drined, nd tends to e droughty t times during the growing seson. The lerut ws treted with n eril pplition of heriide in lte August 987 to ontrol hrdwood sprouts nd hereous vegettion. Deomposition of the forest floor ourred fter the stnd ws hrvested, nd when the study ws estlished, the thikness of the forest floor hd diminished onsiderly. One-hundred-eight squre plots, 6 ft on side, were estlished fter the 987 growing seson. Seedlings were numered using luminum tgs, nd the root ollr dimeter nd height of eh seedling were mesured. The residul mixture ws pplied to the plots t () rtes of nd pproximtely.4, 4.8 nd 9.6 dry tons per re (susequently referred to s rtes,, nd 3), () in either lte My, lte July, or lte Septem- er, nd (3) for one, two, or three yers in suession. The mixture ws 5% sludge nd 75% sh on dry weight sis. The sh ws generted y the iomss oiler t the Gret Northern mill in Est Millinoket, nd the sludge ws otined from the wstewter tretment plnt serving the sme mill. The first set of tretments ws pplied in lte My 988 nd the lst in lte Septemer 99. The mixture ontined most of the elements required for tree growth. The most notle hrteristis of the mixture were lium ronte equivlent of 3%, nitrogen onentrtion of.%, lium onentrtion of 5%, nd ph of. Portions of the lerut, inluding ll of the plots, were treted with seond pplition of heriide in lte August 989. Root ollr dimeter ws mesured fter the onlusion of eh growing seson, from 987 through 99. Root ollr dimeter mesurements were disontinued fter the 99 growing seson, nd stem dimeter mesurements were mde t height of ft fter the 99 nd 994 growing sesons. After the 994 nd 995 growing sesons, stem dimeter mesurements were mde t rest height. Future dimeter mesurements t rest height will ontinue. Seedling height ws mesured fter the 987 growing seson, nd height growth ws mesured fter the 988, 989, 99, nd 99 growing sesons. Height growth mesurements were disontinued fter the 99 growing seson. Smples of urrent yer folige were tken from seedlings in ll plots eginning fter the 988 growing seson nd in eh sueeding yer through 99. Folige smples were lso olleted fter the 994 nd 995 growing sesons. The folige from individul seedlings ws omined to form omposite smple for eh plot. Folige smples were oven dried t 65 o C for 4 hours nd ground in Wiley Mill to pss through -mesh sieve. The smples were nlyzed for the following elements: nitrogen, phosphorus, lium, potssium, mgnesium, oron, iron, opper, zin, luminum, nd mngnese. Anlyses were performed in the Anlytil Lortory of the Deprtment of Applied Eology nd Environmentl Sienes, University of Mine, Orono. Nitrogen, phosphorus, potssium, lium, nd mgnesium re required y plnts in reltively lrge mounts. The reminder, exept for luminum, re required in muh smller mounts. Aluminum is not known to e required for plnt growth (Krmer nd Kozlowski 979), ut hnges in folir luminum onentrtions re frequently inditive of hnges in soil ph. 3

5 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 Cross-Setion Growth (in. ) Applition Rte (dry tons/) Cross-setion Growth (in. ) Applition Rte (dry tons/) Figure. 99 root ollr ross-setion growth of lk sprue seedlings treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens with the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) The dt were nlyzed using nlysis of vrine to test for the signifine of tretment effets. When the nlysis showed signifint effet, Tukey s Studentized Rnge Test t P =.5 ws used to sertin whih tretments were signifintly different. Signifint, s used in this report, indites sttistilly signifint differene t P =.5. RESULTS AND DISCUSSION Seedling Growth Stem ross-setion nd dimeter growth A mrked differene in root ollr ross-setion growth mong pplition rtes ws oserved fter the 989 growing seson, ut the effet ws not signifint until the onlusion of the 99 growing seson. The effet ws lso signifint for growth during the 99 growing seson (Fig. ) nd for the four-yer period, 988 through 99 (Fig. ). During tht four-yer period, growth of the ontrols ws 4% greter thn growth of seedlings in the rte 3 plots. The trend t eh mesurement period eginning in 989 ws one of deresing ross-setion growth with inresing pplition rte. In ll figures, the overll men for given rte is sed on the mens of ll plots tht reeived tht rte, irrespetive of numer of pplitions or time of pplition. The numer of pplitions did not influene root ollr ross-setion growth signifintly until the 99 growing seson, ut the effet of numer of pplitions ws muh less thn the effet of pplition rte. Growth ws gretest in plots treted one nd lest in plots treted twie. The differene etween plots treted two or three times Figure. Four-yer (988 through 99) root ollr ross-setion growth of lk sprue seedlings treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) ws not signifint. For the four-yer period 988 through 99, the numer of pplitions resulted in no signifint differenes, lthough the sme trend existed s during the 99 growing seson. The redution in growth with suessive inreses in pplition rte is ttriuted primrily to ompetition from hereous vegettion, the growth of whih ws stimulted mrkedly y pplition of the residul. No redution in the onentrtion of ny folir element inluded in the nlyses ppered to e lrge enough to ount for the growth deline. As explined elow, oth luminum nd mngnese showed redued onentrtions eginning in 989. How- Cross-setion Growth (in. ) Applition Rte (dry tons/) Figure 3. Three-yer (99 through 994) rosssetion growth t stem height of ft of lk sprue treted with mixture of wood sh nd seondry ppermill sludge. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) 4

6 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT DBH (in.) DBH (in.) Applition Rte (dry tons/) Figure dh of lk sprue treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) Applition Rte (dry tons/) Figure dh of lk sprue treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) ever, luminum is not required for plnt growth nd mngnese is only required in smll mounts. The sme generl growth trend s desried ove ontinued t the -ft stem height during the three-yer period 99 through 994 (Fig. 3). During this time, growth of the ontrol trees ws 38% greter thn growth of the rte 3 trees. Although growth ontinued to derese suessively with inresing pplition rte, the differene etween rtes nd ws not signifint nor ws the differene etween rtes nd 3. Threeyer growth t rte ws % greter thn t rte. The pplition rte effet on ross-setion growth tht ourred t nd ner the stem se ws evident t rest height fter oth the 994 (Fig. 4) nd 995 (Fig. 5) growing sesons. The overll effet on dh ws signifint. In oth yers the rte trees hd the lrgest dh nd the rte 3 trees hd the smllest dh. After the 994 growing seson, the solute differene ws smll, eing only.3 in., ut the reltive differene ws %. After the 995 growing seson the solute differene etween the sme tretments ws.6 in., nd the reltive differene ws 9%. It thus ppers tht eight yers fter the first tretments were pplied, the effet of pplition rte, exerted primrily through effets on ompetition, my hve leveled off. The numer of pplitions did not ffet dh fter either the 994 or 995 growing sesons. Height growth Height growth exhiited the sme trend over time s ross-setion growth, deresing in eh growing seson fter the first, s pplition rte inresed. However, the effet of pplition rte ws not sttistilly signifint in ny individul yer. The effet of pplition rte on height growth ws signifint, however, for the entire four-yer period (Fig. 6). Seedlings in the ontrol plots outgrew seedlings in plots tht reeived the mximum rte y 5 in. After the 99 growing seson, seedlings in the ontrol plots verged 58 in. tll, nd seedlings in the rte 3 plots verged 53 in. tll. There ws no effet of numer of pplitions on height growth, lthough there ws very wek trend of deresing height growth with inresing numer of pplitions. Time of pplition ws not signifint, nor were ny of the intertions. Height growth mesurements were stopped fter the 99 growing seson euse of the limited tretment effet nd euse some of the trees were more thn 7 ft tll, mking mesurements urte enough to detet smll tretment effets very diffiult nd time onsuming. The reltively greter effet of pplition rte on root ollr ross-setion growth thn on height growth is evident in the perentge differenes etween seedlings from the ontrol plots nd seedlings from the rte 3 plots. In 99, rosssetion growth of the ontrols ws 45% greter thn the rte 3 plots, nd in 99 it ws 57% greter. In ontrst, height growth of the ontrols ws % greter in 99 thn in the rte 3 plots nd 5% greter in 99. For the four-yer period, ross-setion growth of the ontrols ws 4 % greter thn for the rte 3 seedlings, wheres height growth ws only 4% greter. 5

7 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 Tle. Level of signifine (n.s. = not signifint) nd diretion (inrese [+] or derese [-]) of tretment effets on elementl onentrtions of lk sprue folige Growing Seson nd Tretment Element Nitrogen n.s. n.s. n.s. n.s. n.s. n.s..- n.s. n.s. n.s. Phosphorus n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s..+ n.s. Clium n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. n.s. Potssium n.s. n.s..+ n.s..+ n.s..+ n.s..+ n.s. Mgnesium n.s. n.s..+ n.s..+ n.s..+ n.s..+ n.s. Iron n.s. n.s. n.s. n.s. n.s. n.s..- n.s. n.s n.s. Boron.+ n.s Mngnese n.s. n.s..- n.s..- n.s Aluminum n.s. n.s..- n.s Copper n.s. n.s. n.s. n.s..- n.s..- n.s. n.s. n.s. = pplition rte -,.4, 4.8, 9.6 dry tons/; plots were pooled y rte irrespetive of numer of pplitions or time of pplition = numer of pplitions -,, or 3; plots were pooled y numer of pplitions irrespetive of rte or time of pplition Folir element onentrtions The effets of oth pplition rte nd numer of pplitions inresed through the 99 growing seson nd were still redily pprent t the onlusion of the 994 growing seson (Tle ). Time of pplition nd the vrious intertions were not signifint, with severl exeptions. All three possile trends in element onentrtions ourred with inresing pplition rte either n inrese or derese or no hnge. All elements inluded in the folige nlyses were present to vrying degrees in the sh nd sludge mixture, nd n inrese in folir onentrtions of t lest some elements might e expeted simply euse they were dded to the soil. In ddition, the vilility of some elements inreses s soil ph inreses (idity dereses). Inluded mong these elements re nitrogen, phosphorus, lium, potssium, nd mgnesium (Brdy 974; Prithett nd Fisher 987). The vilility of other elements dereses s soil ph inreses. Inluded mong these elements re iron, oron, opper, mngnese, luminum, nd zin (Brdy 974; Prithett nd Fisher 987). Results for folir element onentrtions re presented for the period 988 through 99, nd for 99 nd 994. Folir element onentrtions 988 through 99 Boron ws the only element signifintly ffeted y tretment in 988, inresing s pplition rte inresed. This runs ounter to the reported trend of deresing oron onentrtion with inresing ph (Tisdle nd Nelson 975; Fisher nd Prithett 987). Boron onentrtions in 988 were lso relted to time of pplition. Conentrtions in the folige of seedlings treted in oth lte My nd lte July were virtully identil, 8.4 nd 8. mg/kg, respetively. Conentrtion in the folige of seedlings treted in lte Septemer ws. mg/kg. This ws the only instne in ny yer in whih time of pplition ws signifint for ny element. Nitrogen onentrtions in 988 folige verged.95%. This is ove the onentrtion required for good to very good growth of lk sprue (Swn 97) nd suggests tht growth would not hve een inresed y the nitrogen dded to the site in the sludge-sh mixture. In smples tken fter the 989 growing seson, mgnesium nd oron were signifintly higher t one or more non-zero rtes, nd mngnese nd luminum onentrtions were signifintly lower (Tle ). Boron onentrtions were lso signifintly inresed y the numer of pplitions, eing higher in plots treted twie thn in plots treted only one. In the 99 growing seson potssium nd opper onentrtions were lso signifintly ffeted y pplition rte, with potssium eing higher nd opper lower t one or more non-zero rtes (Tle ). Both oron nd luminum onentrtions were signifintly ffeted y numer of pplitions (Tle ). Boron onentrtions inresed suessively s the numer of pplitions inresed, nd luminum onentrtions were lower in plots treted three times thn in plots treted either one or twie. Folir element onentrtions--99 The mximum effet on folir element onentrtions oserved t ny time ourred in foli- 6

8 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 Height Growth (in.) Applition Rte (dry tons/) Figure 6. Four-yer (988 through 99) height growth of lk sprue seedlings treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) ge smpled fter the 99 growing seson, when seven elements displyed either inresed or deresed onentrtions t one or more non-zero rtes (Tle ). Conentrtions of potssium, mgnesium (Fig. 7), nd oron were signifintly higher t some rtes, nd onentrtions of nitrogen (Fig. 8), luminum (Fig. 9), mngnese, nd opper were signifintly lower. There ws lso distint trend of lower iron onentrtions with inresing pplition rte, ut differenes mong rtes were not signifint. The redution in nitrogen onentrtions is ttriuted to some uptke of tht element y the dense, hereous vegettion in the treted plots. The differene etween the pplition.). Mgnesium Conentrtion (%) Applition Rte (dry tons/) nd Yer Figure 7. Mgnesium onentrtions in 99 nd 994 folige of lk sprue treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) ontrol nd mximum pplition rte plots ws smll, however, eing only.%. Aluminum onentrtions in ontrol plots were pproximtely 5% greter thn in the rte 3 plots, nd mngnese onentrtions were more thn twie s gret in ontrol plots s in the rte 3 plots. Redutions in luminum, mngnese, nd opper re presumed to e due t lest prtly to n inrese in soil ph, whih redues the vilility of those elements for plnt uptke. The redutions in oth luminum nd mgnesium re quite lrge, however, reltive to the mgnitude of the ph hnges. Nitrogen Conentrtion (%) Applition Rte (dry tons/) Figure 8. Nitrogen onentrtions in 99 folige of lk sprue treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of Aluminum Conentrtion (mg/kg) Applition Rte (dry tons/) nd Yer Figure 9. Aluminum onentrtions in 988, 99, nd 994 folige of lk sprue treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) 7

9 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 Aluminum Conentrtion (mg/kg) Numer of Applitions nd Yer ph d Applition Rte (dry tons/) Forest floor Minerl soil Figure. Aluminum onentrtions in 99 nd 994 folige of lk sprue treted with mixture of wood sh nd seondry ppermill sludge for one, two, or three yers in suession. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y numer of pplitions irrespetive of rte or time of pplition.) Figure. 99 ph of the forest floor nd minerl soil treted with mixture of wood sh nd seondry ppermill sludge t four rtes. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y rte irrespetive of numer of pplitions or time of pplition.) The numer of pplitions of the mixture signifintly ffeted onentrtions of oron, mngnese, nd luminum (Tle ). Boron onentrtions inresed s numer of pplitions inresed, nd luminum (Fig. ) nd mngnese onentrtions deresed s numer of pplitions inresed. The inrese in oron proly ourred euse more ws pplied s the numer of pplitions inresed. Redutions in luminum nd mngnese likely resulted prtly from higher soil ph tht ourred with two or three pplitions. Inreses in ph of oth the forest floor nd minerl soil, ut espeilly of the forest floor, ourred fter the tretments were pplied. ph of the forest floor proly inresed (idity deresed) lmost immeditely fter tretment, euse the mixture eme prt of the forest floor very quikly. Anlysis of forest floor smples olleted in My 989, pproximtely one yer fter the first tretments were pplied, showed signifint effet on forest floor ph, with differene of.39 ph units etween untreted plots nd rte 3 plots. It should e emphsized tht onsiderle deomposition of the forest floor hd ourred y the time tht the first set of tretments ws pplied, nd the uffering effet of the forest floor ws proly redued. The 988 tretments used no effet on ph of the minerl soil. After the third yer of tretments (99 growing seson--smples tken in My 99), the sme trend in forest floor ph persisted mong pplition rtes s fter yers nd (Fig. ). The differene etween ph of the highest rte nd the ontrol ws.8 units. The effet on ph of the minerl soil, whih ws first deteted to e signifint in smples tken in My 99 ws lso signifint in the 99 smples. For minerl soil the differene etween ph of the highest rte nd the ontrol ws.7 units. This ws lrger differene thn the.5 units oserved fter the seond growing seson, ut it ppers to e too smll to hve hd mjor effet on nutrient vilility. After the 99 growing seson (smples tken in My, 99), there ws signifint effet of numer of pplitions on forest floor ph ut not on minerl soil ph (Fig. ). ph inresed suessively s numer of pplitions inresed. Although the differene in ph of.5 units etween two nd three pplitions ws not sttistilly signifint, it proly ws due to the effet of numer of pplitions. There re severl points to onsider regrding the oserved dereses in folir nutrient onentrtions. One is the degree to whih hnges in ph of the minerl soil tht ourred t some distne from the trees ws representtive of the hnges tht ourred djent to, nd possily within, the pper ontiners in whih the seedlings were plnted. It is likely tht during the first yer or two of the study the root systems were still lrgely onfined to the ontiners nd the djent soil. Movement of infiltrting wter, whih proly ontined some of the sludge nd sh mixture, long the oundry etween the ontiners nd the soil, nd possily through the ontiners, my hve ffeted ph nd therefore, the uptke of 8

10 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 ph Numer of Applitions Forest floor Minerl soil Nitrogen Conentrtion (%) Yer Figure. 99 ph of the forest floor nd minerl soil treted with mixture of wood sh nd seondry ppermill sludge for one, two, or three yers in suession. The first tretments were in My 988. Mens hving the sme lower se letter re not signifintly different (P =.5). (Plot mens were pooled y numer of pplitions irrespetive of rte or time of pplition.) elements whose vilility is funtion of ph, more thn ws the se in the soil overll. Although this my hve een ftor erly in the study, y the 99 growing seson, the fourth of the study nd the sixth sine the seedlings were plnted, nd espeilly y the 994 growing seson, expnsion of the root systems into the surrounding soil should hve minimized ny lrge ph effets tht my hve ourred in nd djent to the pper ontiners during the erly stges of the study. Another point reltes to the distriution of the seedling roots in the minerl soil nd the hnge in soil ph with depth. If mny fine feeder roots re loted in the upper portion of the minerl soil immeditely elow the forest floor, nd if the ph of this soil is higher thn the overll verge for the top 4 in. of the B horizon, then ph effets on element vilility my e greter thn would e expeted sed only on the verge ph of the upper 4 in. of the B horizon. Folir element onentrtions 994 After the 994 growing seson (seventh growing seson fter the first pplition), tretment effets on folir element onentrtions were still evident, ut there were some differenes from 99 (Tle ). Nitrogen nd opper onentrtions were no longer signifintly ffeted y pplition rte. There ws still wek trend of deresing iron onentrtions with inresing pplition rte. No suh trend ws evident for either nitrogen or opper. Mgnesium (Fig. 7), oron, potssium, nd phosphorus onentrtions were ll signifintly inresed y pplition rte. Neither phosphorus nor potssium showed Figure 3. Trend over time of nitrogen onentrtions in urrent-yer folige of lk sprue treted with mixture of wood sh nd seondry ppermill sludge. Yerly mens were lulted from the mens of ll plots, inluding the ontrols. tretment effets t ny smpling time prior to 994. The long-term effet of pplition rte on folir element onentrtions is evident in the nlyses on folige of trees from plots treted only in 988. In 994, onentrtions of five elements mgnesium, phosphorus, oron, luminum, nd mngnese were ll signifintly relted to pplition rte. Mgnesium, phosphorus, nd oron ll inresed t one or more non-zero rtes, nd luminum (Fig. 9) nd mngnese deresed. Conentrtions of potssium inresed with inresing pplition rte, lthough the effet of rte ws not signifint. Conentrtions of potssium, oron, luminum, nd mngnese were ll relted to numer of pplitions (Tle ). Potssium nd oron inresed signifintly s numer of pplitions inresed, nd onentrtions of luminum (Fig. ) nd mngnese deresed signifintly s numer of pplitions inresed. Conentrtions of potssium nd oron were highest in plots treted three times nd lowest in plots treted one. However, the differenes mong numer of pplitions were smll nd proly of no prtil importne. Conentrtions of oth luminum nd mngnese deresed with inresing numer of pplitions. Aluminum onentrtions were out % lower in plots treted three times thn in plots treted only one, nd mngnese onentrtions were nerly % lower. For oth elements the effet of numer of pplitions ws less pronouned fter the 994 growing seson thn fter the 99 growing seson. The 994 growing seson ws the fourth fter the lst set of 9

11 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 tretments ws pplied, nd it is resonle tht during tht time, some tretment effets would hve diminished. ADDITIONAL ASPECTS Nutrient Conentrtions The yerly flututions in folir nitrogen onentrtions tht ourred from 988 through 994 re noteworthy; the men nitrogen onentrtion for trees from ll plots hd dropped to.% in 994 from high of.9% fter the 988 growing seson (Fig. 3). There were lrge hnges in nitrogen onentrtions during the first three yers of the study. The high onentrtion in 988 my hve een due to omintion of residul effet from fertilizer remining in the ontiners, relese of nitrogen from forest floor deomposition, nd uptke of pplied nitrogen. The drop of nerly.5% from 988 to 989 my hve resulted from derese in the effet of the fertilizer in the ontiners nd lrge inrese in the uptke of nutrients y the hereous vegettion, whih ws extremely dense during the middle nd lte portions of tht growing seson. The rise in 99 my hve een due to the uptke of nitrogen relesed y deomposition of hereous vegettion killed y the August 989 heriide pplition. Redutions in nitrogen onentrtions sine 99 re proly due to regrowth of hereous vegettion nd inresed lk sprue folige mss. It should e stted, however, tht y 995 the lk sprue hd inresed to suffiient size nd the stnd to suffiient density in mny ples so s to sustntilly redue the growth of hereous vegettion. Nitrogen onentrtions ove.6% re onsidered dequte for good to very good growth of sprue (Swn 97). A onentrtion of.% is onsidered not suffiient for good growth. The lower nitrogen onentrtions oserved in 99, nd espeilly in 994, suggest tht the stnd my either hve entered, or will soon enter, stge of development in whih growth my e limited y insuffiient nitrogen. Low nitrogen onentrtions frequently limit the growth of sprue nd fir on mny sites in Mine. Conentrtions of ll other mronutrients (lium, potssium, phosphorus, nd mgnesium) were generlly suffiient for good to very good growth during the entire period, sed on riteri estlished in greenhouse studies (Swn 97). Mgnesium ws the exeption, eing present in folige of trees from ontrol plots t onentrtions suggesting slight defiieny t ll smpling times. This slight defiieny ws llevited y pplition of the residul. It is not possile to omment on the suffiieny of other elements reltive to the onentrtions in whih they re required euse riteri for those elements re not ville. It should e emphsized tht seven elements sulfur, molydenum, hlorine, sodium, olt, vndium, nd silion ll of whih hve een found to e essentil to the growth of some plnts (Tisdle nd Nelson 975), were not inluded in the folir nlyses of this study. Approprite Time for Applition of Sludge nd/or Ash The redution in growth tht ourred in this young lk sprue plnttion following pplition of the sludge nd sh mixture rises the question s to the stge of development during whih stnd my enefit most from n pplition of sludge nd/or wood sh. From the stndpoint of ese of pplition, tretment of stnd within severl yers of estlishment is desirle. However, it is unlikely tht very young onifer stnd will show inresed growth to n pplition t tht time for severl resons. One is relted to the ft tht plnted seedlings my hve een germinted nd rised in ontiners to whih fertilizer ws dded. There ould e rryover effet of this fertilizer fter the seedlings were plnted, whih might redue or eliminte possile growth enefits from the residul. Another reson is tht the rte of deomposition of the forest floor inreses following removl of the overstory. This mens tht nutrients my eome ville to seedlings in reently plnted lerut t rte equl to, or greter thn, tht required y the seedlings. A third onsidertion is the nutrient requirements of onifers ompred to those of ompeting hrdwoods nd hereous vegettion. The ompeting vegettion hs higher nutrient requirements thn the young onifers nd is, therefore, more likely to enefit from dded nutrients. Stimultion of ompeting vegettion my use redued growth of onifers nd ould neessitte dditionl vegettion ontrol efforts. In ddition, where the growth of onifers is limited y nutrient defiieny, nitrogen is usully the nutrient tht is defiient. There is little or no nitrogen in wood sh. Seondry sludge, whih is reltively high in nitrogen, would hve to e dded in order to stisfy nitrogen defiieny. In short, there ppers to e little reson to expet tht the growth of newly estlished onifer stnds will e inresed y the ddition of nutrients. The pplition of nutrients t, or shortly efore, rown losure presents greter opportu-

12 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 nity to inrese growth. At out the time of rown losure, individul trees re produing new folige t rpid rte. If nutrients do not eome ville rpidly enough to stisfy the needs of the trees, some loss of growth my our. Therefore, ddition of sludge nd/or sh t this time my e enefiil to growth. Sludge, nd espeilly sh, hve high ph, whih is likely to use inresed deomposition of the forest floor whih would furnish n dditionl supply of nutrients. However, orridors would hve to e ut through the stnd to provide ess for the spreding equipment. The other stge of stnd development during whih pplition of sludge nd/or sh might inrese growth is the mture stge tht ours numer of yers fter rown losure. Over time the weight of the forest floor inreses, nd s this ours the mount of nutrients tied up in the forest floor inreses. This is espeilly true of nitrogen, insuffiient mounts of whih limit the growth of older onifer stnds in Mine. Applition of high nitrogen sludge with low ron:nitrogen rtio should led to improved growth. Applition of sludge low in nitrogen nd with high ron:nitrogen rtio my hve the opposite effet. Applition of wood sh might lso inrese growth, euse the high ph of the sh will inrese the minerliztion rte of the forest floor nd the relese of nitrogen. As previously stted, ess orridors would hve to e ut for the spreding equipment. A numer of onerns rise with pplition of sludge or sh t this stge of stnd development. These inlude limited spreding distne due to the high stnd sl re, possile rsion or other dmge to the rk of some trees, root dmge to the trees long the orridors, nd windthrow long the orridors. SUMMARY AND CONCLUSIONS A mixture of wood sh nd seondry ppermill sludge ws pplied t rtes of nd pproximtely.4, 4.8, nd 9.6 dry tons/ to plots in lerut plnted to lk sprue two yers efore the first tretments were pplied. The mixture ws pplied t three different times during the growing seson nd for one, two, or three yers in suession. The sludge nd sh mixture signifintly redued stem ross-setion growth of the plnted lk sprue. The redution in growth eme more pronouned s pplition rte inresed. During the period 988 through 99, trees tht were not treted grew 4% more thn trees tht reeived the mximum rte. The sme trend existed from 99 through 994, with ontrols surpssing the rte 3 trees y 38%. The effet of the tretments ws plinly evident in dh mesurements mde fter the 994 growing seson. Trees in ontrol plots hd dh tht ws. in. greter thn the rte 3 trees. Slower growth in the treted plots ws proly due to ompetition from vegettion tht ws stimulted y the mixture. The effet on height growth ws muh smller thn the effet on stem ross-setion growth. From 988 through 99, height growth of the ontrol trees exeeded tht of the rte 3 trees y only 5 in., whih ws less thn %. The effet of the tretments on folir element onentrtions ws highly vrile: some onentrtions inresed, some deresed, nd some remined unhnged. Boron onentrtions inresed during the first yer of the study, nd mgnesium onentrtions inresed nd luminum nd mngnese onentrtions deresed during the seond yer. The mximum effet on folir element onentrtions ourred during the fourth yer when potssium, mgnesium, nd oron inresed, nd nitrogen, luminum, mngnese, nd opper deresed. The redution in nitrogen is ttriuted to uptke y the dense, hereous vegettion in the treted plots. However, the differene etween the mximum rte nd the ontrol ws only.% (.4% vs..5%). Redutions in luminum, mngnese, nd opper were proly due t lest prtly to inresed forest floor nd minerl soil ph, whih redued the vilility of those elements for plnt uptke. After the seventh growing seson following the first pplition mgnesium, oron, potssium, nd phosphorus onentrtions inresed with inresing rte, nd onentrtions of luminum nd mngnese deresed. Reltive dereses in luminum nd mngnese were muh lrger thn reltive inreses in the other elements. An importnt finding ws the grdul derese in nitrogen onentrtions over time. After the first growing seson, the verge nitrogen onentrtion for ll plots ws pproximtely.9%. After the seventh growing seson the verge nitrogen onentrtion ws pproximtely.%. This is well elow the onentrtion required for good growth of lk sprue, sed on Swn s (97) riteri. This suggests tht the plnttion hs entered developmentl stge in whih growth my e limited y insuffiient nitrogen. Conentrtions of other elements were generlly suffiient for good growth.

13 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 LITERATURE CITED Brdy, N.C The nture nd properties of soils: Eighth edition. Mmilln Pulishing Co., In. New York, NY. Krmer, P.J., nd T.T. Kozlowski The physiology of woody plnts. Ademi Press. New York, NY. Prithett, W.L., nd R.F. Fisher Properties nd mngement of forest soils: Seond edition. John Wiley nd Sons. New York, NY. Swn, H.S.D. 97. Reltionships etween nutrient supply, growth, nd nutrient onentrtions in the folige of lk sprue nd jk pine. Pulp Pp. Res. Inst. Cn., Pointe Clire, Que. Wdlds. Pp. 9. Tisdle, S.L., nd W.L. Nelson Soil fertility nd fertilizers: Third edition. Mmilln Pulishing Co., In. New York, NY.

14 MAINE AGRICULTURAL AND FOREST EXPERIMENT STATION MISCELLANEOUS REPORT 45 3