Comparison of Incorporated and Non-Incorporated Cover Cropping with an Organic Sunflower Fuel Project

Final Report for FNE10-702

Project Type: Farmer
Funds awarded in 2010: $11,694.00
Projected End Date: 12/31/2010
Region: Northeast
State: Pennsylvania
Project Leader:
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Project Information


Green Alchemy Farm chose to enter the field of sustainable fuel production by the successful growing,harvesting,cleaning,pressing and purifying in a small scale operation of oil-seed sunflowers.Oil -seed sunflower’s unique non-GMO oil functioned as the source of the raw, pressed straight vegetable oil(SVO).Our focus in this project was the comparison of two organic techniques of sunflower production:Incorporated vs Non-incorporated cover cropping.

Method #1 ,Non-incorporation,involved the roller crimping of rye and forage peas w/no-till planting.

Method#2,Incorporation,involved the rotovation of rye and forage peas with traditional planting and follow-up cultivation.

Five replications were planned for this study to help establish any statistical trends.We compared the two methods by first taking tissue samples at 32 days and 61 days post planting and sent them to Penn State University’s Agricultural Analysis Lab. Secondly, we compared bulk weight yields between the 2 groups at harvest.Thirdly, we pressed the sunflower seeds from both groups and compared oil yields using a Komet CA59G oil press.Fourthly, we submitted the seeds from each replication for whole seed and extruded pellet nutritional analysis to Skyview Labs in Jennerstown,Pa. Fifthly, we analyzed the oil quality as a SVO fuel by sending representative samples of each experimental group to R.W.Heiden Assoc. in Lancaster,Pa. Our conclusion is that both techniques would have had comparable yields and oil quality on a normal rainfall year if the non-incorporated mulching was seeded heavy enough and planted on a flat seed bed.

However, in a droughty year, the incorporated cover-cropping would be superior allowing the fast availability of nutrients to the young vegetative sunflowers.The non-incorporated group would perform suboptimally because drought would prevent the nutrient rebound expected later on by preventing the gradual deterioration of the mulch to usable nutrients.This is confirmed by the lower Crude Protein values in the Non-incorporated seeds vs the Incorporated groups’ seeds. Moreover,the oil quality analyses would suggest better fuel quality, unfiltered, for the non-incorporated produced seeds vs the incorporated produced seeds.


Green Alchemy Farm chose to enter the field of sustainable fuel production by successful growing,harvesting,cleaning,pressing and purifying in a small scale operation of oil-seed sunflowers. Oil-seed sunflower's unique non-GMO oil functioned as the source of raw, pressed straight vegetable oil(SVO). Our focus in this project was the comparison of two organic techniques of sunflower production: Incorporated vs Non-incorporated cover cropping.

Method#1, Non-incorporation, involved the roller crimping of rye and forage peas w/no-till planting.

Method#2,Incorporation,involved the rotovation of rye and forage peas with traditional planting and follow-up cultivation.

Five replications were planned for this study to help establish any statistical trends.
-We compared the two methods by first taking plant tissue samples 32days and 61 days post planting.
-Secondly,we compared bulk weight yields from the 2 groups at harvest.
-Thirdly, we cold expellor pressed the sunflower seeds from both groups and compared oil yields using a Komet Ca59G oil press. --Fourthly, we submitted the seeds from each replication for whole seed and extruded pellet nutritional analysis.
-Fifthly , we analyzed the oil quality as a SVO fuel taking a representative sample from each of the 2 experimental groups.

Farm Description

Green Alchemy farm is an 88 acre ,Pennsylvania Certified Organic(PCO) farm,located in Berks,Co., PA. We presently grow Limousin cattle,Berkshire pork,grass-fed turkeys and chickens, sunflower oil and hay for outside markets. Green Alchemy is also involved in Green education involving renewable energy and sustainable living ( ).

Green Alchemy had a few wonderful,experienced technical advisors and cooperators in this project. Mena Hauta, the Berks Co. Extension agent gave support and provided the scales for bulk weight yield determination at harvest. Ron Hoover of Penn State University provided invaluable advice on how to set up the study. Denyce Matlin of the Penn State Plant Tissue Analytical Lab provided the needed input on the proper sampling technique for our sunflower leaf analyses. John Schmidt of the USDA-ARS-Pasture Systems and Watershed Management Unit at Penn State University provided invaluable statistical analysis of our raw data. Sjoerd W. Duiker,PhD,CCA of the Department of Crop and Soil Sciences ,Penn State University, provided invaluable initial evaluation of the vegetative tissue samples. Rich Heiden of R.W.Heiden Assoc. in Lancaster provided interpretation of the oil quality of our sunflower oil as a SVO Fuel. And last ,but not least, Tim Bock of Kutztown,Pa. provided the necessary no-till planter and roller-crimper experience for this project to run smoothly.


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  • Mena Hautau


Materials and methods:

In the Fall of 2009 at Green Alchemy farm, we broadcast 2 bushels per acre of cereal rye over freshly moldboard-plowed fields that were to be used in this study. On March 21,2010 we drilled 100#/acre of organic 4010 Welter forage pea in all fields involved in this study (see photos 1,2,17).

In late April 2010 we set up 5 replications of Incorporated (I) and Non-incorporated (NI) groups. Each replication had the same acreage,same field and was randomly determined.
-Field 13 had 2 replications:13I(1),13NI(1),13I(2),and 13NI(2), all encompassing 3.6 acres.
-Field 15 had 2 replications:15I(1),15NI(1),15I(2),and 15NI(2), all encompassing 2.7 acres.
-Field 16 had 1 replication:16I(1),16NI(1) encompassing 0.9acres.

On May4,2010 the Incorporated groups were all mowed with a rotary mower because the rye was getting too tall for rotovation alone (see photos 3,4,19).

On May 8-10,2010 we rotovated down all Incorporated groups using a Maschio rotovator,giving us a 1-2 week window for decomposition prior to planting( see photos 5,6,18). At this time we were waiting for the Anthesis or flowering stage of the rye for Roll-down (see photo 8).

On May 20,2010 we performed 3 functions: the broadcasting of 400#/acre of Fertrell 3-4-7 organic fertilizer over all fields (see photo 10), the broadcasting of 500#/acre of Aragonite (See photo 11), and the planting of untreated ,Seeds 2000 Defender Plus-NT Nusun sunflower seeds at 7 1/2 inch spacing on 30inch rows giving a seeding density of 28,000 seeds/acre. The Non-incorporated groups were planted using a JD6430 tractor with a front mounted I&J Roller-Crimper and a rear mounted Monosem no-till planter(see photos 12-16). The Incorporated groups were planted with the same planter minus the roller-crimper (see photo 27). Two cultivations were performed on all incorporated groups by a pair of Haflinger Draft horses on June 7-8 (See Photo 28) and a Farmall C with front and rear mounted cultivators on June 27th, 2010(see photos 29-31).

Plant tissue leaf samples were collected randomly from all groups on June 21st(32 days post planting)while sunflower plants were in the vegetative stage(See photo 32,33) and July20th,2010 (61 days post planting)when the sunflower plants were in bloom( See Photos 34,35).

Incorporated sunflowers were blooming on July 14th and the Non-incorporated group bloomed 1 week later (Additional Photos 36: 13(2)I Full Bloom wilting and 37: 13(2)NI with weeds). Bird control was instituted the 2 weeks prior to harvest using a rotating propane boomer.

All sunflower seeds were harvested with a JD6620 combine with a JD653A row-crop header on September 4-5,2010 with seed moisture content near 10%(See Photos 9,20-23). All groups had the middle 6-rows combined first to eliminate edge effects. These samples underwent bulk weight determination and representative samples were taken for later seed,extruded pellet and oil analysis.

Seed cleaning was performed on September 8th by subcontracted AgSeed cleaning( See Photos 24-26).

On November 9,2010 all groups' seeds were pressed by a Komet CA59G press (See Photo 7) and seeds and extruded pellets were sent for nutritional analysis. Moreover, extruded oil volumes were measured for each group and two representative samples from the combined Incorporated group and combined Non-incorporated group were sent for SVO fuel quality analysis.

Research results and discussion:

Our results from this project showed some significant differences between the two experimental (treatment) groups. First, the June 21st plant tissue analyses (see Table 1) indicates that nitrogen(N) is 0.5% higher,Iron (Fe) almost 100ppm higher, and Aluminum (Al) about 80ppm higher in the incorporated (I) than the non-incorporated (NI) treatments. Differences were consistent between all replications. When cover crop biomass is incorporated, the material is rapidly decomposed and nutrients contained in the biomass released. In contrast, the nutrients in the biomass left on the soil surface(mulched) will be released more slowly. This is the likely explanation of the higher concentration of N in the I treatment.

In 2010 the contrasts may have been greater because of the dry weather;the decomposition of surface mulch is even slower than in a normal year. From this point onward, the roles should be reversed;greater quantities of nutrients should be released in the mulched treatment because the I biomass has already decomposed. The difference is not in fertilizer value, but the dynamics of release:faster with incorporation, more gradual over the season when mulch is left. You would also expect to see less signs of heat stress with the NI cover cropping. The higher Iron and Aluminum contents of the plant samples may be due to soil contamination:in the I treatments, there is more soil splash onto the plants and this may explain the results in the June 21st samples. Moreover,Sufficiency Ranges from agronomic and plantation crop interpretative values (see Table 2) for sunflowers from 25 mature leaves from new Summer growth shows that both treatment groups in this study were well within the acceptable ranges.

Second, there were not any statistical differences between treatments at bloom taken from the July 20th plant tissue analysis (see Table3). This would suggest the drought of the summer of 2010 prohibited the nutrient rebound expected for the NI(mulched)group.

Third, analysis of the sunflower seeds(see Table 4) shows some statistical differences. The Crude Protein(CP) and Digestible Protein(Dig.P) is slightly higher with the I treatment, which might suggest that there was more N available with the I treatment. This is confirmed possibly by the higher grain yields of the I vs NI treatment(see Table 5). There is also a statistical difference for Calcium(Ca) and Phosphorus(P). The I treatment had a higher Phosphorus value of 0.74% vs 0.71% in the NI treatment. Moreover, The NI treatment had higher Calcium values at 0.36% vs 0.29% I treatment. This apparent difference is hard to explain and may not be important.

Fourthly,there was only one statistical difference for the extruded sunflower pellets (see Table 6). Potassium(K) was greater for the NI treatment. I have no explanation for this difference.

Fifthly,There were some interesting differences in Oil Quality between the two treatment groups (see Table 7). Quality Standard for Rapeseed Oil as a Fuel(RK-qualitats standard,Table 8) is included for comparison. The H sample is the NI treatment group. Because the use of Cetane number as a marker of fuel quality for DIN purposes is now considered invalid, we have provided data on composition variables that can be used to gauge the quality of the oil, the extent of thermal,oxidative and hydrolytic degradation that have a bearing on combustion, fuel flows during cold conditions, and storage stability. The higher oxidative stability numbers of 7.48 and 6.92 it-hours shows that our oils are very resistant to degradation vs the min of 5.0. Both samples were higher than the acceptable viscosity of 38mm2/sec: I value of 39.21 and 38.63 for NI sample; this may relate to the unfiltered diglycerides in the samples. A high acid number was found with the I sample of 4.20 vs 1.80 NI. vs 2.0max. This could cause higher gumming, corrosion and could be caused by a hydrolytic degradation by aging, processing or bacterial. There was a higher moisture value for the I sample at 0.21 vs 0.10 NI vs 0.075 % mass max. Moisture is bound or can have some solubility in oil. There was not a statistical difference in the seeds dry matter between the two experimental groups suggesting seed moisture is not the explanation for the difference.

The Ash was higher in the I sample at 0.064 vs 0.004 NI vs 0.01 %mass max. Ash would represent calcium/magnesium or salts. We see 1.96% mass I vs 1.04 NI samples with measurement of diglycerides. This could be a sign that there was some hydrolytic degradation of the oil to diglycerides from the triglyceride oil structure. This could be because of hot H2O,enzymes or other sources of hydrolysis.

The ToTox measurement is used to assess oxidation of sample. the I sample was 26.9 vs 10.1 NI sample. Canola/rapeseed have lower values. All these oil quality results and differences could relate to submitted unfiltered samples because not enough oil was available to run through our bag and cartridge filtration system. I can not explain the other differences. However, all results suggest a better oil quality for the NI produced oil vs I produced oil, unfiltered. This may be significant as to oil differences related to fuel quality and how they were produced-----but still is unexplained.The flash point of sunflower oil was not determined, but is around 274'C, higher than rapeseed and could connote more power as a SVO fuel.

Lastly, Table 9 correlates to oil yield results for each sample group. (See discussion in Economics section below.)


The major condition during the project that probably had a significant impact on our results was the Summer drought of 2010.

This had a speculative impact on the study in a number of ways.

-First, as noted above in the results, the drought would contribute to a an attenuation of biomass degradation on the non-incorporated group, which we saw blooming 1 week later than incorporated group and not having any rebound of nutrients on second plant tissue samples of July 20th and lower Crude & Digestible protein values for the NI seeds.

-Secondly, the drought dropped our yields considerably, but especially with the non-incorporated groups.

-Thirdly, did the drought have an effect on the oil quality by encouraging hydrolysis and higher diglycerides in the I oil, which could ultimately effect fuel quality with higher viscosity? We see more degradation changes in the incorporated group's oil and this may relate to that group's delay for harvest 1 week longer to accommodate the NI groups longer time to maturity.

The second conditional impact was that the Welter forage peas 4010 did not all die with the roller-crimping. This would allow the peas to continue growing till maturity or being killed by the drought. This would affect the sunflower vegetative growth 2 ways: competition for available nutrients,thus inhibiting growth ,but also presenting to a lesser degree,a continued source of nitrogen fixation that would promote sunflower vegetative growth.We believe that it was the irregular surface in the NI treatment group that prevented adequate crushing of the peas, but it could have been the resistant nature of this pea variety?

Thirdly,the no-till planting of sunflower seeds into an uneven surface(the mold-board plowed field) created an unforeseen non-controlled variable in the experiment. The I groups were seeded into relatively flat seed beds.

Fourthly, the rate of 2 bushels per acre cereal rye was too low for adequate mulching to provide weed control. We would recommend 3 1/2 bushels/acre of rye alone or slightly less with additional peas. This failure ,plus the drought, caused an explosion of the late summer annual weeds like ragweed.


The obvious economic advantage to this project is the ability of a farmer to grow his own fuel. Converting a diesel engine to run on vegetable oil(SVO) is safe and can be done by any relatively handy individual. As compared to Biodiesel, where one converts the fuel to fit the engine, safety is a primary concern: toxic chemicals,fire hazards, and the safe disposal of non-fuel related byproducts (glycerol and methanol-laden water from washing fuel). Moreover, one loses about 20% of the energy value of the vegetable oil in the form of glycerol during the conversion to Biodiesel.

Most referenced oil yields for oil-seed sunflowers puts a maximum potential value of around 99 gallons per acre pre-pressing. In our project, we were seeing a 55% press efficiency resulting in around 330ml/1# Incorporated seed. With our yields on this dry year we produced around 62 gallons of SVO per acre with the Incorporated treatment group. This value should be higher during a regular year and can be increased on press type and speed of extrusion. The production of the extruded pellet as a valuable product beyond the oil must not be understated. The extruded pellet can serve three potential uses: raw feedstock for ethanol production,valuable feed source with a crude protein of around 26%, and as a biomass fuel with a high BTU.

Oil-Seed Sunflowers can be grown organically in southeastern Pennsylvania and can serve as a valuable energy crop. I believe on a normal year both experimental techniques would yield similar yields and crop quality. However, one must follow the rules of adequate mulch with 3 1/2 bushels/acre of cereal rye(less with peas) and a level planting surface. Economically, the NI group would save significant amounts of fuel and in addition, would be more ecologically friendly in preventing erosion and fuel combusted . Moreover, this study suggests a possible higher fuel quality for SVO produced with this experimental group.

Research conclusions:
Assessment and Adoption

We were trying to compare two different organic techniques for the production of Oil-Seed Sunflowers in southeastern Pennsylvania. I believe , even though yield data says otherwise, that on a normal rainfall year, I would expect similar seed yields using these two methods. One must use adequate seeding numbers to mulch for weed suppression. We had poor weed suppression in the NI experimental groups because we should have used higher rates of rye(3 1/2 bushel per acre vs 2 bushels). The rye should be drilled NOT broadcasted and an addition of a legume, possibly field peas /fava beans/ or Austrian winter peas,can be planted if previous year's crop was not a nitrogen fixator ie. alfalfa hay.

On my farm, most of the time I am not planting sunflowers into a previously harvested legume field and need to support the sunflower growth with a nitrogen fixator to push up nitrogen for growth. If I were and one can afford the equipment, the roll-down/crimping / no-till technique is reasonable. For me, I need the immediate boost of nutrients from incorporation, here by rotovation of the rye and peas for fast growth of the sunflowers and the sidedressing of appropriate levels of Organic fertilizer.

As shown in the nutrient analysis of the sunflower leaves, we were attaining adequate nutrient levels using both techniques in the vegetative stage , but more with incorporation as seen with higher N, Fe,and Al. I will continue to use these two techniques on the farm, only altering the roll down technique with higher rye seeding and roller-crimping on a flat surface . This is especially important to guarantee good seeding thru the mulch and proper crushing of the rye and especially the peas.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

Our plans for this project were/(will be) presented at 3 programs:
NOFA New York 2010 Annual Conference, MAALACT Annual Conference 2010 at Alvernia College and PASA Southeast 2011.A publication of an Organic Farmer's Handbook for Oil-Seed Sunflower Production is in production and should appear in late Spring /Summer 2011.

Project Outcomes

Assessment of Project Approach and Areas of Further Study:

Potential Contributions

We have shown that a small,organic sunflower to fuel project is feasible in southeastern, Pennsylvania using either an incorporation or non-incorporation of rye/pea cover cropping. It is also feasible to broadcast rye and drill peas into a mold-board plowed field as long as incorporation of the cover crop is planned ie.rotovation. This method will save fuel consumption by the elimination of disking. But most energy would be conserved by using the non-incorporated cover-cropping technique sown into a previous legume field ie clover hay. In-row weed control using buckwheat which would be dropped over vegetative sunflowers at second cultivation was postulated to help control the late summer weeds ,like ragweed. This practice will be tried during 2011.

Future planting of the sunflowers on 15inch rows will also be tried to determine weed-control and yield potential.In addition,the use of Fava beans as the legume instead of forage peas offers a superior nitrogen fixation if seeds were readily available.Also,the simultaneous planting of Austrian winter peas with the rye could eliminate a second planting in the Spring,IF ,a mild Winter is commonplace. Finally, I believe very few studies exist comparing organic production techniques and the evaluation of the fuel quality of the generated organic SVO. The evaluation of vegetable oil for fuel is novel and this study can provide a starting point for acceptable guidelines of sunflower oil fuel.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.