Advancing Cover Crop Systems in Ontario - Focus on Soil Nutrients (N+P), Soil Health, Insects and Nematodes

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1 Purpose: Advncing Cover Crop Systems in Ontrio - Focus on Soil Nutrients (N+P), Soil Helth, Insects nd Nemtodes OSCIA Tier 2 Grnt St. Clir Region Cover crops hve numerous documented benefits including reducing soil erosion, incresing soil orgnic mtter, inhibition of pests nd ltering nutrient vilbility. The populrity of using severl cover crop species in mix is incresing, thus this project ws estblished to compre cover crop multi-species mixes to single species or simple mixtures in terms of vrious functions. The objectives of this project were: 1. To compre cover crop multi-species mixtures to single species or simple mixtures in terms of biomss growth 2. To determine the nitrogen credit of selected cover crop mixtures to the following corn crop 3. To mesure the impct of cover crops on phosphorus loss. Determine the impct of vrible freeze-thw mgnitude on dissolved rective phosphorus (DRP) export b. Find cndidte cover crop species which best resist the impct of freezethw cycles (FTC) c. Determine the effect of erly termintion of cover crops (vi glyphoste ppliction) hs on DRP export compred to leving plnts green 4. To study the impct of cover crops on insects, slugs nd soyben cyst nemtode (SCN) 5. To promote the use of cover crops nd provide informtion on how to grow cover crops successfully Methods: Multi-species mixtures: Three smll plot, intensive sites, were setup in Winchester, Ridgetown nd Thmesville. All three sites hd four replictions with 22 different tretments. Tretments included no cover check plot nd 21 different cover crop mixes rnging from 2-14 species per mix. Additionlly, t Ridgetown nd Thmesville, 6 tretments were dded to ech repliction for totl of 28 tretments per repliction. The dditionl 6 tretments were mixtures of rdish, ots nd crimson clover t vrying rtios to determine if seed rtio hd n effect on totl biomss or individul species germintion nd growth. Tble 1 lists ll the species used in the mixes. Additionl to the three smll plot sites, eleven stellite loctions were estblished. These loctions were strip tril plots with vrying number of tretments nd replictions, Tble 1 lists the vrious species used in these trils. The size of the plot nd species used in mixes ws t the discretion of the coopertor. Tble 2 lists the eleven loctions nd the type of tril being performed t ech. 1

2 Tble 1: List of cover crop species used in smll plot nd stellite loction mixes Species ots berseem clover pes rye sweet clover Brssic (kle/turnip) rdish lentils nnul ryegrss hiry vetch flx sorghum sudn crimson clover phceli mustrd sunflower mung ben sunnhemp red clover buckwhet brley fb bens triticle chickling vetch white clover cowpe chickpe Tble 2: List of the eleven stellite loctions nd the type of tril t ech Loction Type of tril Florence compring seeding rtes of 3-wy mix Thmesville Nitrogen tril Amherstburg Nitrogen tril Chthm compring species rtios in 3-wy mixes Lkeshore compring 3, 6, 9 nd 12 -wy mixes comprison of different cover crop mixes Wtford nd no cover comprison of cover crop mixes tht will Kingsville not overwinter comprison of cover crop mixes tht will Highgte not overwinter Strthroy compring 3, 6, 9 nd 12 -wy mixes comprison of different cover crop mixes Chthm nd no cover comprison of cover crop mixes tht will Petroli not overwinter All loctions were plnted fter whet hrvest between mid-august nd mid-september. Counts of ech species present in ech mix were conducted t the three smll plot loctions in September to determine germintion nd compre with expected rtios from the seeding rtes. Counts were conducted by counting the number of ech species present in two 0.25m 2 qudrts per plot. Biomss hrvest ws done t ll smll plot nd stellite loctions, except for two, between mid-october nd the beginning of December. Two loctions were not smpled due to lck of dequte growth or vilbility. Smpling ws done by collecting ll bove ground biomss in two 0.25m 2 qudrts per plot (the sme ones s used for plnt counts) for the smll plot loctions, nd three 0.25m 2 2

3 qudrts per strip for the stellite tril loctions. All biomss ws dried to constnt moisture nd totl dry weight biomss ws recorded. Cover Crop Nitrogen Credit: The two nitrogen tril sites consisted of field-scle strips with check (no cover crop) strips nd strips of cover crop mixture. In order to isolte the nitrogen credit, no cover crop check versus plnting cover crop mixture replicted 4 times ws estblished. In the spring of 2016, corn will be plnted with five nitrogen rtes to determine the nitrogen credit if ny from the cover crop. Phosphorus: To dte, lbortory experiment hs been conducted to exmine the effects of cover crop species, type of freeze-thw cycle, nd the effects of termintion prior to freezing on phosphorus export. These vribles were tested for both phosphorus nd nitrogen relese. Much of the lb work hs been completed nd two conference presenttions (IAGLR, CGU) re in preprtion. The field component of the phosphorus study will begin in the fll of At present, series of field trils hve been initited on the University of Wterloo cmpus to determine n pproprite set of instrumenttion for the leching studies. We re currently seeking co-opertor nd field for the trils to begin in lte Insects: In the spring of 2015 smpling ws performed in cover crop trils t seven loctions to ssess insect presence. These loctions hd strips of cover crop mixtures nd within ech strip, two 0.25m 2 holes were dug to depth of 6. The soil from these holes ws exmined by hnd nd ll insects were plced in 95% ethnol nd trnsported to the lb for identifiction. SCN: With the increse in cover crops usge nd interest in field crops it is importnt to understnd if the cover crop species listed in tble 1 re indvertent hosts for plnt diseses nd nemtodes. In 2015, the sme cover crop species were plnted in two loctions (Highgte nd Rodney) nd ssessed for suitbility s host for Soyben cyst nemtode (SCN - Heteroder glycines) nd root lesion nemtode (RL- Prtylenchus penetrns) s well s the fungl disese sudden deth syndrome (SDS- Fusrium virguliforme). Promotion of Cover Crops: Demonstrtion frms will be estblished to show different cover crops nd their mngement. Presenttions will be mde t vrious soil nd crop nd other meetings Results: Multi-species mixtures: All sites hd some level of cover crop estblishment by lte November; however stnd qulity nd totl growth vried widely. The vrible growth, s well s difficulties in estblishment could be in prt due to the lck of moisture seen t nd fter plnting. At the three smll plot loctions (Ridgetown, Thmesville nd Winchester) totl dry mtter vried between ,875 lbs/c. While t the eleven stellite loctions totl dry mtter vried between 852-9,625 lbs/c. Compring cross ll tretments t the three smll plot loctions there ws no significnt difference in cover crop biomss dry weight between mixes with 3, 6, 9, or 10+ species (Figure 1); however, biomss dry weight in ll cover crop plots ws significntly higher thn the no cover plots where volunteer whet ws the only species present. Additionlly 3

4 there ws no correltion between incresing number of species in the mix nd totl dry weight biomss. Counts of species present in ech tretment were lso performed t the smll plot loctions. Comprison of the expected number of plnts per qudrt nd the ctul count ws performed; however, this did not pper to be simple method of determining best mix or predicting growth. Further nlyses of these counts my provide insight into determining which mixes provide the most diversity. Furthermore, these counts my help with economic nlyses of mixes. Dry Weight Biomss (lb/c) b Number of Species in Mix Figure 1: Averge cover crop dry weight biomss for mixes with vrying number of species t three smll plot loctions. Biomss vlues followed by the sme letter were not significntly different t the 5% level. The eleven stellite trils were ll set-up slightly differently due to grower preference. Consequently it ws difficult to compre totl dry weight biomss cross loctions. Furthermore, hrvest times vried between loctions with t lest 6 weeks seprting the erliest hrvested loction nd the ltest. This increses the difficulty in ccurtely compring cover crop growth cross loctions. Figure 2 is grph of ll tretments t ll loctions orgnized by number of species in the mix (1-12). Similr to the smll plots, there ws no correltion between number of species in the mix nd totl dry weight biomss nd there ws no significnt difference in cover crop biomss dry weight between mixes with 3, 6, 9, or 10+ species. 4

5 Totl Dry Weight Biomss (lbs/c) Figure 2: Cover crop dry weight biomss for ech tretment cross ll sites. The number on the x-xis represents totl number of species in the mix nd ech colour represents different loction. Two loctions (Strthroy nd Lkeshore), llowed for comprison of totl biomss dry weight cross 3, 6, 9 nd 12 wy mixes. The 6 nd 9-wy mixes t these two sites hd significntly higher biomss s compred to the 3-wy mix, while the 12-wy mix ws not significntly different thn ny of the other mixes Dry Weight BIomss (lb/c) b b Number of Species in Mix Figure 3: Averge cover crop dry weight biomss for 3, 6, 9 nd 12-wy mixes t two strip tril loctions. Biomss vlues followed by the sme letter were not significntly different t the 5% level. Insects: Anlysis of pest by tretment hs not yet been completed but some generl observtions cn be stted. Millipedes mde up the vst mjority of the specimens 5

6 found t the reserch sites. Millipedes cn be considered both beneficil for breking down orgnic mtter nd s pests, choosing to feed on crop seeds if conditions re idel. Wireworm specimens were sent to Wim vn Herk, Agriculture nd Agri-Food Cnd, Agssiz, B.C. for species identifiction. All seven loctions hd wireworms present t vrying degrees of infesttion. A totl of sixty-five wireworm specimens collected (Figure 4). Interestingly, ech loction ws mde up of predomintely one wireworm species insted of combintion of wireworm species. Overll, the most bundnt wireworm found ws the estern field wireworm, Limonius gronus. As for other insects or pests found, slugs were next most bundnt, though popultions were below dmging levels nd few (n=3) predtory ground beetles or lrve were cptured. Figure 4: Wireworm species collected from cover crop sites in 2015 SCN: At both loctions (Highgte nd Rodney), SCN reproduction ws only observed on the brodlef legume, crimson clover nd t very low levels. Roots were lso processed to determine the verge number of SCN lrve (juveniles) in the root. Hiry vetch hd the highest number followed by red clover. The other clovers (sweet yellow, crimson nd white) long with fb bens hd the low levels of SCN lrve in the roots. No SCN lrve were found ssocited with brssice nd grss cover crop roots. Although these results from this one yer study show low or little risk for SCN reproduction it is importnt to note tht brodlef legume cover crop species such s hiry vetch, red clover, field pe, crimson clover, white clover, sweetclover nd fb beens hve been reported to be SCN hosts. In ddition to plnting SCN resistnt vrieties, growers who use these species should routinely tke SCN nemtode smple to note chnges in nemtode popultion levels. Root lesion nemtodes were detected in ll 26 cover crop species rnging from high of over 15,000 nemtodes per grm of root to low of 75 nemtodes per grm of root. Seven cover crop species hd root lesion numbers verged bove 1000 nemtodes per grm of root. The highest by fr ws Sunn Hemp which ws over 15,000 nemtodes/g root followed by Field pes (7,352) nd Fb Bens 4,072). Four other 6

7 cover crop species hiry vetch, white clover, red clover nd orientl mustrd rnged from 1,921 to 1,429 root lesion nemtodes per grm of root wheres the remining 19 cover crop species were ll below 1,000 nemtodes per grm of root. Sunn Hemp hs been shown to be effective ginst vrious nemtode species prticulrly those nemtodes which sty nd feed in one plce in the root system (sedentry endoprsitic nemtodes) such s root knot nemtode (Meloidogyne spp) nd SCN. This study will be repeted in Promotion of Cover Crops: Presenttions were mde t Essex, Kent nd Lmbton Soil nd Crop nnul meetings. No demonstrtion frms were estblished. The St Clir Region Conservtion Authority Soil nd Wter tour visited one site. Summry: Cover crop mixes plnted fter winter whet hrvest cn produce vrible mounts of biomss depending on moisture, timing of plnting nd time of hrvest. Fll hrvest biomss rnged from ,875 lbs/c. After one yer of evluting cover crop biomss nd plnt counts, it is difficult to determine the optiml mixes. Initil nlysis of 3, 6, 9 nd 12-wy mixes suggest 6 nd 9 wy mixes will produce the lrgest mount of biomss; however, further studies re needed to nlyze this reltionship. Finlly, extremely vrible biomss between tretments nd loctions did not llow for dequte comprison of mixes to determine optiml species mix nd rte. Next Steps: Dt nd lbortory nlysis is ongoing for smples collected in the fll of SCN counts from collected soil smples re currently being done. Anlysis of plnt counts is ongoing to evlute cover crop mixes. In the spring of 2016 cover crop residue will be recorded. Further soil nd plnt smpling will be done in 2016 nd corn yield will be mesured. Anlysis of 2015 nd spring 2016 dt will be used to optimize mix choice for the 2016 plnting of cover crops fter winter whet. Acknowledgements: Thnks to the co-opertors for their commitment to plnting these plots. The funding for this project ws provided by the OSCIA Tier II grnt, regionl grnt from the Southwest Agriculturl Conference nd from Innovtive Frmers of Ontrio. Thnk you to Spere Seeds for supplying the seed t discounted price. Thnks lso to Clire Coombs for her ssistnce with project design, dt nlysis nd biomss hrvest. Project Contcts: Adm Hyes, OMAFRA, dm.hyes@ontrio.c Anne Verhllen, OMAFRA, nne.verhllen@ontrio.c 7