INTENSIFYING THE CORN-SOYBEAN ROTATION WITH THE USE OF WINTER RYE FOR BIOMASS ENERGY PRODUCTION Peter Sexton, Lon Hall, Mike Plumer, Bob Berg, & Jesse Hall, Plant Science Dept., SDSU

Corn – Soybean Timeline

Advantages of growing rye between corn and soybean crops: Provide biomass or forage production Help protect the soil from erosion and improve soil quality Help suppress winter annual weeds Diverse market opportunities (hay, grain, fuel) Low establishment cost – flexible entry and exit for producers Does not seriously disrupt grain crop cycle

Soil microbial biomass in May following oat/rye, and annual grass, cover crops established the previous season in comparison to a control (fallow) treatment. Data are from an Ohio study with no-till corn harvested for silage (Fae, et al., 2009).

Average concentration of nitrate in soil leachate from side by side plots in Maryland. Each bar is a five-year average for the first reading of the year (January) from 1991 through 1995 (redrawn from Staver and Brinsfield, 1998).

Methods and Approach Compare method of rye establishment (in progress) inter-seeding into corn direct seeding after corn harvest after corn hybrids with varying maturity Measure rye biomass production Evaluate effects on yield of the following soybean crop Work has been initiated at three sites: SDSU Northeast Research Farm (45o N latitude) SDSU Southeast Research Farm (43o N latitude) Carbondale, Illinois (38o N latitude)

Corn grain yield of five different hybrids ranging in maturity from 75 to 112 days relative maturity at Beresford, SD in 2012, 2013 and 2014. 2012 season (drought affected) 2013 & 2014 seasons

Broadcast Drilled

Comparison of rye biomass production for broadcast seeding during late grain filling and direct seeding after harvest at Beresford, SD. Rye was harvested in the spring of 2013. There were no significant differences in rye biomass production between these treatments.

Soybean yield in 2013 following rye biomass crops established with broadcast and drill seeding along with a control (no rye) treatment. Soybean yield differences were statistically similar in this study.

Comparison of rye biomass production for broadcast seeding during late grain filling and direct seeding after harvest at Beresford, SD. Rye was harvested in the spring of 2014. The drilled rye had greater biomass than did the broadcast rye. The rye following 75 day corn did better than rye planted after later corn lines.

Soybean yield in 2014 following rye biomass crops established with broadcast and drill seeding along with a control (no rye) treatment. The soybean crop following rye basically failed due to excessive June rainfall.

Soybean Yields Following Winter Rye Biomass Crop In a Severe Drought Season (2012) – Beresford, SD Treatment Rye Wt. Soybean Yield (lb/ac) (bu/ac) rye-biomass crop 2770 4.9 no-rye control ---- 20.1 Mean 12.5 P value p<0.05 CV (%) 45.2 Ecological efficiency The handout diagram is not to scale: much more is usually lost to conversion than this Typical conversion values Less than 1% of solar energy absorbed by plant Grazing herbivores Consume 30-50% of Pplant Only assimilate only 20-50% of what they consume Carnivores Assimilate more of what they consume: 80-90% But spend much more of it on Respiration, and store less away as their own P example, small birds and mammals burn up about 98% of their consumption on respiration Plant products fed to cattle in feedlot contain about 0.5% of the solar energy that reached teh plant; protein in consumed meat of the cattle contains 0.8% of energy in their feed; 1 lb edible meat = 125 lbs feed

Rye Biomass and Following Soybean Yields in Carbondale, IL – 2014 Season Line Rye Biomass Soybean Yield (lb/ac) (bu/ac) 79-08 4340 23.0 Triticale 3922 27.7 VNS 3091 27.5 Rymin 2793 29.9 Hazlet 1681 34.4 Control --- 30.7 Mean 3165 28.9 CV (%) 23.4 LSD (0.05) 533 NS Ecological efficiency The handout diagram is not to scale: much more is usually lost to conversion than this Typical conversion values Less than 1% of solar energy absorbed by plant Grazing herbivores Consume 30-50% of Pplant Only assimilate only 20-50% of what they consume Carnivores Assimilate more of what they consume: 80-90% But spend much more of it on Respiration, and store less away as their own P example, small birds and mammals burn up about 98% of their consumption on respiration Plant products fed to cattle in feedlot contain about 0.5% of the solar energy that reached teh plant; protein in consumed meat of the cattle contains 0.8% of energy in their feed; 1 lb edible meat = 125 lbs feed

Soybean yield plotted against rye biomass production for different rye genotypes. Carbondale, IL – 2014 Season Ecological efficiency The handout diagram is not to scale: much more is usually lost to conversion than this Typical conversion values Less than 1% of solar energy absorbed by plant Grazing herbivores Consume 30-50% of Pplant Only assimilate only 20-50% of what they consume Carnivores Assimilate more of what they consume: 80-90% But spend much more of it on Respiration, and store less away as their own P example, small birds and mammals burn up about 98% of their consumption on respiration Plant products fed to cattle in feedlot contain about 0.5% of the solar energy that reached teh plant; protein in consumed meat of the cattle contains 0.8% of energy in their feed; 1 lb edible meat = 125 lbs feed

Rye Biomass & Soybean Yields – Initial Reflections: With extremely dry (2012) or wet (2014) weather, the rye biomass crop put the following soybean crop at risk. In the more typical 2013 season we did observe any negative impacts on soybean yield. For corn maturity versus date of rye planting, we did not find a good “nick” or “sweet spot” where corn maturity can be shortened to promote rye biomass production without hurting corn yield. Relative success of broadcast seeding rye depends on fall weather. The new rye lines shows promise for greater biomass production; however, there were trends in Illinois for higher rye biomass production to be associated with lower yield of the following soybean crop. At this point, it seems to me that rye as an energy crop is not consistent enough to establish a processing industry around it. As a supplementary source of biomass it would have a place (my opinion).

Estimated Cost of Rye Biomass Production Item cost per acre Seed $25.00 (1.6 bu/ac @ $16/bu) Planting $15.30 Windrow $12.50 Baling $31.25 Moving Bales $3.30 P&K Replacement $22.00 Cost per Acre $109.35 Yield (tons/ac) 1.75 Cost per ton $62.49