Evaluating the Impacts of Stripper Stubble on Corn Yields in NW Kansas Year 3 (2008)

Transcription

1 Evaluating the Impacts of Stripper Stubble on Corn Yields in NW Kansas Year 3 (2008) 12 th Annual Kansas Agricultural Research Association (KARA) Conference January 22 and 23, 2009 Salina, Kansas Kastens Inc. Farms Rawlins County, Kansas RR 2 Box 83 Herndon, KS (785)

2 In NW Kansas, water (soil water at planting and inseason rainfall) is the most limiting factor in corn production. Small-plot research at Akron, Co. and Tribune, Ks. suggest that using a stripper head for wheat harvest increases yields for the following corn or grain sorghum crops due to the inherent water savings characteristics of the taller stubble. Project Objectives Use a 32 Shelbourne Stripper header for harvesting part of the 2005, 2006 and 2007 winter wheat crops. Collect detailed planting and harvest data from the 2006, 2007 and 2008 corn crop. Evaluate the impact that stripper stubble has on ensuing fall crop yields across these three years. 2

3 Year Description was a slightly above average wheat year for us as wheat across the farm averaged bu/ac (49.95 bu/ac fallow wheat, bu/ac wheat on wheat, and bu/ac wheat on corn) was a wipe-out corn year with an average yield of bu/ac (range was 0 to 88 bu/ac). The grain sorghum was also below average with a yield of bu/ac (71.08 bu/ac on wheat ground and bu/ac on corn ground). Year Description was a much below wheat year for us as wheat across the farm averaged bu/ac (33.14 bu/ac fallow wheat, 9.04 bu/ac wheat on wheat, and 3.2 bu/ac wheat on corn) was a much above average corn year with an average yield of bu/ac (range was 84 to 135 bu/ac). The grain sorghum was also above average a yield of bu/ac ( bu/ac on wheat ground and bu/ac on corn ground). 3

4 Year Description was a much above average wheat year for us as wheat across the farm averaged bu/ac (64.82 bu/ac fallow wheat, bu/ac wheat on wheat, and bu/ac wheat on corn) was an above average corn year with an average dryland yield of bu/ac (range was 31 to 137 bu/ac). The grain sorghum was below average with a yield of bu/ac (71.08 bu/ac on wheat ground and bu/ac on corn ground). Data Collection -wheat Wheat harvest is our only operation where we still follow the contours of the land based on the man-made water retention terraces. Over 30% of our 2005, 2006 and 2007 wheat crops were harvested using the Shelbourne stripper. To ensure accurate analysis, special care was given to ensure that large enough areas within each field were harvested as well as representative areas. After harvest, the yield monitor data were calibrated back to scale tickets and then archived for use in this study. 4

5 Thirty-two foot Shelbourne stripper on John Deere 9760 STS. Data Collection Fall crops Farmworks SiteMate was used to collect all planting information associated with a John Deere row in 2006 and 2007 while a JD GS was used in 2008 with a JD row planter. Harvesting was accomplished using two John Deere 9600 combines, each running GreenStar yield mapping systems in 2006 and 2007 while two John Deere 9760 STS machines were used in After harvest, the planting and harvest data were merged and two additional identifiers were added to each harvested data point. Headland presence (any point within 100 of the field boundary) Stripper vs. straight cut 5

6 Planting in 50+ bu/ac stripper cut wheat stubble. Close-up of planted stripper stubble. The cap is lying directly on the corn row. 6

7 Close-up of planted running in stripper stubble. Analysis In 2006, all data points were used and each field was aggregated and treated as a side by side. For 2007 and 2008, true in-field side by side comparisons were made across all fields and crops that had stripper stubble present using 0.50 acre grids. A total of 17 test sites were used in 2007 and 24 test sites in No headland areas were included in the analyses and an attempt was made not to collect from areas where other research plots were located or across different hybrids (a different hybrid for each of the 0.50 acre side by side aggregation grids. Standard paired t-tests were used for evaluation. 7

8 Analysis Results Corn Yield in Strip Yield in Straight Adv. Strip PTtest PTtest Obs (bu/ac) (bu/ac) bu/ac) Pval. Confidence % % % 8

9 Results In 2006 (a very poor corn year) we saw an advantage of 5.35 bu/ac for corn grown in stripper stubble. This relationship was significant at p<0.05. In 2007 (a very good corn year) we saw no yield advantage to corn planted in stripper stubble. In 2008 (a slightly above average corn year) we saw a 9.59 bu/ac advantage for corn grown in stripper stubble. This relationship was significant at p<0.05. Results In poor to above average corn years, there is a significant advantage to planting corn on stripped wheat stubble as opposed to straight cut stubble. Perhaps we would have seen similar results in the much above average 2007 corn had populations been higher as ample rainfall and timing minimized moisture related yield limitations. Some research has suggested that the yield advantage due to straw height is reduced with increased straw density. In 2008, we had many fields with high straw density and the results were mixed in that in some of these fields there was still an advantage to straw height while in others there was none. 9

10 Quick Take Cont. Milo Our base rotation involves planting cont. milo into corn stalks so this year I pulled side by sides looking at 2008 milo yields that were planted in areas that were stripped wheat in Across 10 observations I found a yield advantage of 5.26 bu/ac for 2008 milo planted after 2007 corn that had been planted into stripped 2006 wheat. The relationship had a pval of only (confidence = 80%) which does not mean it is significant at p<0.05, but it is not to far off. The wheat stubble in 2006 was very poor in general so it will be interesting to evaluate this component next year as our 2007 wheat stubble was far superior to that of Quick Take Cont. wheat As we explore more cropping intensity options in Western Kansas a rotation that is beginning to find favor is wheat on wheat. Often this rotation involves the 1 st year of wheat being re-cropped into corn stalks and the 2 nd year involves planting cont. wheat into the re-cropped wheat stubble. The recropped wheat stubble is often very thin and often must be harvested to the ground with straight cut platforms. I pulled six observations this year from our cont. wheat on re-cropped wheat to see whether there was a yield advantage in the 2 nd year of wheat based on whether it was on stripped or straight cut stubble. Across these six side by sides I found a yield advantage to the stripped stubble of 4.22 bu/ac. With a pval of 0.13 (confidence of 86.80%) the relationship was not significant at a p<0.05 level, however it (like the milo) is not far off and probably justifies further exploration. 10

11 Quick Take Cont. wheat Quick Take Cont. wheat 11

12 Final Thoughts Our 2008 wheat crop was 100% harvested using stripper heads. The results from 2008 further justify that we made the correct decision in moving away from straight cut heads. What we like about stripper heads Optimal residue distribution behind the machines Improved harvest efficiency and ability to get down wheat Improved transport from field to field Improved field conditions at planting time (complete, uniform ground cover). Increased corn yields in most years and possibly increased yields throughout a whole rotation. Ability to reduce surface evaporation for multiple years Improved animal habit (good for PR purposes) QUESTIONS? Ideas? MAKE SURE YOUR PLANTING EQUIPMENT CAN HANDLE RESIDUE! kastensinc.com 12