Thursday, May 19, 2011

Corn Harvest

The corn has matured and I've managed to find an 8 row corn front to hire. This is a New Holland front that has been modified to fit a CAT header. We made a simple adaptor in our workshop so it would fit on our Case 2388. If it hadn't been modified it would have actually been simpler to fit. I bought some shorter tubes for our PTOs and they went straight on. Fortunately the owner of this front is not using it this year so we have had plenty of time to get it ready and no rush to send it back.

Case 2388 with New Holland 8 row Corn Front

Grain Dryer
I've also hired a dryer. It's an Agridry FB2000 cross flow batch dryer. In this photo it's hooked up to my Case Puma 155. The dryer holds 20 tonne (800 bu). The tractor PTO drives a blower and a generator. The generator is for the burner which has an electric fuel pump and air blower. The burner runs on diesel. The corn is coming off between 18 and 20% moisture and takes a few hours to dry. The crop was mature (but not dry) early April and I've had to wait a while for the dryer. I think that if we had planted 3 weeks earlier in mid October then harvest could have started in early April. The owner of this dryer wants it back soon so he can start his own corn harvest. We'll also need the dryer later on for our sorghum. For what it's worth the Puma 155 is for sale as I've bought a bigger tractor with a 3m wheel track for CTF. I'll miss the Puma, it's a good all-round tractor. It's been our preferred tractor for windrowing, mowing, baling, spraying and just about everything else. It's a bit small to pull our airseeder but we did end up using it on the chaser bin this year and I prefer it to our larger Magnum for that job.
Case Puma 155 with Agridry FB2000 Grain Dryer

Harvest started on the 5th of May. Heres a photo from the header cab. I'm harvesting the Pioneer 36B08 which is 103 day CRM. I'ts my best yielder this year and I think that maturity length is about right for our area. This is also about the best part of the paddock. Not far to the left of here is an old fence line and once I crossed that the yield drops off. The poorer side was cropped for about 8 years before we started no till in 2006, while the good side had only been cropped for 5 years. Also in 2004 a stubble burn was followed by a strong wind that blew all the ash onto the good side of the fence. The bottom line is that the better side has more organic matter and fertility. I think a bit more urea and potash would have helped.
Harvesting Corn Drivers View

I like this yield monitor photo. It rarely dropped below 5 t/ha (80 bu/a) in the 36B08. I think if you knock off about 10% it would be closer to the truth though. I'll calibrate it when I've finished harvest. Overall I lost about 2 or 3 ha to cockatoos and averaged about 4t/ha (64 bu/a) on the rest. I'm disapointed with the yield as we've had quite a wet summer. The crop did suffer from early waterlogging in places. I applied a total of 70 Kg/ha of Nitrogen which is only just enough for 4 t/ha so N probably limited yield. Plant population was 36,000/ha (14,400/acre) planted, but being sown with an airseeder, spacing was all over the place. Some plants were crowded and only produced small cobs, while there was also some big gaps. Not having a no-till planter available we didn't really have a choice, but I have something organised for next year. Speaking of plant population - the US no-till guys aim for 200 plants/bushel (8000/tonne) so my population was right for 4.5 t/ha (72 bu/a).

The photo below sums up the logistics. I can nearly (but not quite) hold a batch for the dryer in the header and chaser bin. As the dryer has two bins we can unload half and empty the header. Then we can harvest a couple of tonne while the trucks unloading into our silos. The dryer is a big hold up for this job, we have fairly dewey mornings with a fair bit of moisture in the air so I can only get one batch dried per day. Starting harvest a month earlier would make a big difference. I'm not sure how we'd handle a big harvest, maybe a combination of aerated storage and drying. The chaser bin holds about 11 tonne of corn. It holds 12 tonne of good wheat so thats about 450bu. A 25 tonne bin would be better for this job and for filling semi trailers but we mainly use it between the header and silo bags, for which it's perfect.

Plant Spacing
Everyone says that it's important to get plant spacing correct, but nobody could put a figure on how much yield is lost. In the photo below I have 14 cobs taken from 20' of row. The smaller cobs came from crowded plants. These plants could have been placed in gaps between the other plants without compromising them. So I believe that with a precision planter I could have had 14 full sized cobs instead of 10 full size and 4 half sized cobs. This gives me about 17% yield increase.
Uneven Corn Plant Spacing


  1. Ben, this is a great "first effort" for dryland corn. Looks like the waterlogged conditions caused some denitrification.
    If you can get hold of a precision seeder this year you will see another yield jump. Also the new hybrid 36Y84 has outperformed 36B08 in many trials and has improved stalk strength and husk cover.
    Well done overall!

  2. If you made 80 bu an acre with a 14,400 plant population you did good. Yes, get a planter uniform depth and spacing are critical for corn.

    I love longer season Pioneer corn for irrigation, 115 day, but the shorter season, 105 day, doesn't compete with other seed companies. It will be interesting to see how the drought tolerant AquaMax works, we have some in both dry land and limited irrigation this year.