|
| we finally harvested our 30" vs 60" corn plots just over a week ago.
The plots consisted of:
30" row plots w/ interseeded CCs = 6 rows of GH 55G3 x 490'x 3 replications
30" row plots w/o interseeded CCs = 6 rows of GH 55G3 x 490'x 3 replications
60" row plots w/ interseeded CCs = 3 rows of GH 55G3 x 490' (unreplicated)
60" row plots w/o interseeded CCs = 3 rows of GH 55G3 x 490' (unreplicated)
Great Harvest Organics 55G3 was planted on 5/24 w/ a target population of 30k/a on both 30" and 60" rows but we ended up with slightly higher pops in the 30" row plots
The whole field received 2 tons/a of pelletized chicken litter (~110 lbs/a of first year available N) - broadcast on 5/17
The whole field was rotary hoed once and cultivated twice.
A cover crop mix (Iron&Clay cowpeas, medium red clover, yellow sweet clover, crimson clover and Essex rapeseed) was interseeded on 6/25.
Cowpeas were planted with a 1 row push planter and established well. The small seeded CCs were broadcast and established very poorly due to extended drought.
the average plot yields were as follows:
60" spacing (w/ and w/o interseeded CCs) = 150 bu/a
30" spacing (no CCs) = 187 bu/ac
30" spacing with interseeded CCs = 199 bu/ac
************************************************************
Quick conclusions
two 60" row plots (w/ and w/o CCs) had very similar yields (~ 150 bu/a) > 20 % less than the average yield of the 30" row plots
All of the 30" corn plots w/ interseeded CCs outyielded the paired 30" corn plots w/o CCs
3 replications is NOT enough to have a high level of confidence that interseeded CCs enhance corn yield but we now have 2 years of data showing that CCs interseeded into corn @ v5/v6 do not hurt corn yield
cowpea biomass in the 60" plots was ~ 10x the biomass in 30" plots (we are still crunching this data)
************************************************************
We are in the process of designing a much larger scale solar corridor experiment for 2019
We will include a straight 60" treatment but probably at least 2 other configurations (e.g., 2 x 30" rows alternating with 60" gaps, 3 x 30" alternating with 60" gaps, 4 x 30" alternating with 60" gaps) that I expect are more likely to maintain corn yield while enhancing CC growth.
we will definitely stick with cowpeas but may also try some other warm season legume species (e.g., a forage soybean) and may try some plots with a warm season legume planted at the same time as the corn.
Joel
WIU Agriculture | |
|
Yield data - 30 vs 60" corn rows w/ and w/o interseeded cover crops
