March 26, 2013

Agronomist Notes

Hello Reader

Hello spring storms and fog. We may be just five weeks away from planting but the heavy snow pack and cold weather tells me otherwise for most of my territory.

This week in Beyond Agronomy News, we’ll look at how to reduce tramline erosion risk in CTF systems as well as a unique drainage software called OptiSurface that helps reduce soil disturbance up to 85% when cutting and filling! Last, I’ve provided a link to the presentations given at the International CTF conference I attended in Toowoomba, QLD in February. We’ll finish with technical grain market news.

Have a great week.

Jamie Murray of Marania Farms in Kenya sent me this picture of his 30-ft Seedhawk on 10-inch spacing seeding beautifully in-between last year’s stubble. Inter-row seeding is a dream for SeedHawk machines, which generally struggle with handling residue.

Managing CTF's weakest link

Tramline erosion

I frequently talk about the benefits of CTF so today I thought I’d bring up one of the weakest links in CTF, the potential for tramline erosion. With the right combination of slope, soil type and rainfall intensity, tramlines, like you see in the photo from Queensland, AUS can erode. The tramlines with the highest risk are sprayer tramlines as sprayers carry the heaviest load on the narrowest tires during the wettest time of the year. The deep ruts begin to hold more water, which leads to higher erosion risk if they run downhill.

Tim Neale from www.precisionagriculture.com.au addressed this issue at the International CTF conference I attended in Toowoomba, QLD a few weeks back. Tim has provided CTF farm layouts to farmers for over ten years. He now uses software to run erosion analysis to predict which tramlines are most at risk for water ponding and erosion and how to manage them properly. First, Tim points out that there are ways of minimizing the potential for tramline erosion.

Rotate sprayer onto other tramlines where possible.
Use wider tires on sprayers.
Examine tram line layout using RTK GPS data.
Use disk seeders with caution on slopes. Flat surface increases water velocity.
Use wheel track renovators where practical.
Use land leveling to fix core issues.
If possible stick to sprayers with a light footprint.

The tramline erosion simulation software Tim uses is called OptiSurface and is very unique. You can enter in your elevation (must be RTK) and local rainfall data to simulate rainfall patterns along with intensity to see what kind of erosion risk you have as well as area lost due to water ponding. You can also alter rainfall intensity to simulate a worst-case scenario. From there you can determine which direction your tramlines should run to reduce the risk of erosion or which ones you should avoid with the sprayer if possible.

I had Tim run an analysis on our field to see what kind of water ponding would exist if we had 4-inch ruts on our tramlines running north and south. I also had him do the same analysis on tramlines running east west with ruts 4 inches deep. To my surprise, our north/south tramlines with 4-inch ruts would create enough water ponding to cover 56 acres of this field. If we were to switch our tramlines to run east/west running the same scenario we would reduce water ponding by 51% and leave 37 acres of area under water. The erosion risk on this field is low at 0.4 M/sec. (1 M/sec would be considered high erosion risk.)

The two images above provide an example of the water ponding analysis.

To date, we’ve had no issues with tramline erosion, even on our steepest slopes on other fields. This software has pointed out that at least one field has low risk for erosion and I look forward to seeing the results on the rest of our farm. Prevention is the best medicine to cure erosion and knowing where your hot spots are is key. SL

To view the presentation on tramline erosion and the software Tim uses, click here.

Photo and images source: Tim Neale

OptiSurface, revolutionary field drainage software

Water logged soils have cost producers millions in Western Canada over the last five years. Even temporary water logging can cause up to 100% yield loss depending on the crop and length of time under water. There has been a trend towards more site-specific tile drainage and even land leveling to fix drainage problems. While in Toowoomba, Queensland at the CTF conference I was introduced to a unique, world-class drainage software called OptiSurface that has the ability to reduce land leveling soil disturbance by up to 85%.

OptiSurface calculates the optimized field topography while satisfying water management goals and minimizing earthworks. It uses a patented system that incorporates Infinitely Variable Grades™ with 3D GPS machine control technology. The data produced by OptiSurface is then inserted into Trimble’s Field Level II to generate the cut and fill prescription map.

The cost of poor drainage often goes unmeasured, even though we know where the areas are; we rarely calculate how much money is lost. To give you an example, we had a 1M resolution, NDVI image taken of one of our fields in 2011 shown above. The image clearly indicated (in red) we were losing crop yield from poor drainage inside the blue line but had no idea it added up to 65 acres on a 160 acre field! Even at a modest 10% yield loss, poor drainage cost us roughly $2,600 in 2011. My guess would be more like $5,000 in 2011 from excessive moisture in May-June.

I had Tim Neale run this 160-acre field under the OptiSurface program and it calculated that I could gain 6 more acres by cutting and filling and correct the issues I had on the 65 acres that pond temporarily. The cost of the OptiSurface is $1.00 per acre for the surface analysis, which tells you exact field area, cut volume M3, fill volume M3, cut per area M3/ha and minimum slope. I’ve been through this process and it’s fairy simple. The next step is the cut and fill data file that is uploaded into a Trimble FMX with Field Level II software. The Rx map would cost $3.00 per acre plus an approximate cost of $1.50-$2.00 per M3 for a custom contractor with cut and fill capabilities.

Steve’s quick math
6 acres reclaimed × $400/acre gross margin = $2,400
Drainage analysis and cut and fill Rx map: $4.00 ×160 acre field = $640
Cut and fill cost: Cut volume is 790/M3 + 670/M3 fill volume × $2.00/M3 = $2,920
Total cost: $640 + $2,920 = $3,560
ROI: 1.5 years

In this example, I could generate an ROI within 1.5 years at a cost that is reasonable enough to do on a few fields per year. The beauty of the OptiSurface software is that it aims to reduce soil disturbance by calculating the least amount of topsoil moved while still achieving the desired drainage improvements. If you wanted to do your own cutting and filling, the cost of Field Level II by Trimble which controls the blade through an RTK guided FMX controller costs between $6,000 and $8,000 CDN depending on what equipment you’re starting with. Talk to a Trimble dealer for more on costs and set ups.

In the end, I believe the next technology to drive yield higher and add efficiency is proper field drainage. There are millions of acres waiting for small improvements to generate big returns from proper drainage. The OptiSurface software is very unique and the only one on the market that claims up to 85% less soil disturbance, which is massive. SL

If you’re interested in drainage maps or pursuing the OptiSurface service further contact:

Tim Neale: tim@precisionagriculture.com.au
PrecisionAgriculture.com.au

Or

Graeme Cox: graeme.cox@optisurface.com
Director of DAVCO OptiSurface

Pictured above: 1M res NDVI imagery of barley taken at flag leaf 2011.

International CTF presentations now online

The presentations from the first International CTF conference, which I attended in Toowoomba, QLD late February are now online. You can see CTF equipment setups and results in cereal production, vegetable, sugar cane, cotton and even forage production and manure applications inside CTF by presenters from around the world. I highly recommend taking a look through the presentations, it was a great conference. SL

View here