Agronomists Notes
Hello Reader,
Greetings from Kenya! We arrived safe and sound last Friday night to an excellent welcome. Within a few hours of arrival our African adventure was in full swing. We left the airport on a flat-ish tire, stopped at a dodgy gas station to get air, learned thank you and no worries in Swahili, and survived chaotic Nairobi traffic. We arrived at our lovingly prepared stone and thatched roof home before midnight and tucked the family in by flashlight. During that time that we discovered we had left a bag circulating on the luggage carousel. Our hosts the Barden’s live and farm inside a 20,000 acre wildlife conservancy and what we have seen and experienced within a few short days is priceless and a just little surreal.
Kenya appears to be like most developing countries with its chaotic traffic, jalopy vehicles, shanty houses and people chatting on cell phones. The Barden’s have about 100 employees and I think I’ve met most of them already. You’re always greeted with a smile and a handshake. We met Patrick the guard who was on Cheetah watch. He was armed with a digital camera and a three-speed pedal bike. The saying around here is “you don’t have to be fast, you just have to be faster than the guy beside you.”
In this week’s issue of Beyond Agronomy News, we’ll look into a technique called skip row sowing which has the potential to increase yields in the dry Prairies. Next, we’ll look at a lesson in vision and show you Morrin, Alberta gumbo in Kenya. Last, we’ll look at three overlooked production factors that could help us jump off the yield plateau we’re sitting on after zero-till. We’ll finish with technical grain market news.
Have a great week,
Improving crop productivity in dry Prairie regions
Skip row sowing
A few years back I was introduced to a farming technique called skip row sowing by Stuart Barden in NSW, Australia. Skip row sowing is used in drier regions to improve sunlight capture, conserve moisture and increase moisture use efficiency. As the name implies, skip row sowing uses one or two blocked seed runs on alternating rows across the drill or planter. When finished, you’re left with one solid seeded row next to an empty row (single skip) or two empty rows (double skip). This technique has the potential to improve production in some of the drier areas of the Canadian Prairies.
The picture shown here is of Stuart Barden on his new farm near Athi River, Kenya beside a double skip row configuration. With a 30-inch row planter, two rows are planted then two rows are blocked leaving a 60-inch gap between them.
The first thing skip row sowing offers is better sunlight capture. We typically plant on 10 and 12-inch row spacing which creates a fairly dense canopy. A dense crop canopy will shade the bottom half of the crop canopy and reduce its photosynthetic potential. For example, if you were to shade all the leaves on a mustard or canola plant, (picture a thick canola crop in full bloom reflecting light) you could reduce yield by 20% (Trobish and Schilling, 1969). If you were to remove the leaves of those canola and mustard plants completely, you would reduce yield by 50%. On the extreme end, studies have shown that shading wheat at flowering to just 20% of full sunlight reduced grain yield by 50% (DR Kemp and EE Whingwiri, 1980).
The second advantage to skip row sowing is the improvement in moisture use efficiency. A skip row configuration effectively reduces the plant population and allows seeded rows to tap into moisture beside them, pulling moisture horizontally rather than vertically. In effect, you’re doubling the amount of soil moisture available to the crop and accessing it horizontally which requires less energy on the plant’s behalf. The reduction in energy is used to produce grain rather than transport water and nutrients.
If you’re wondering if the concept works, I just walked through a Kabuli chickpea crop on a skip row configuration that will probably yield 15 bu/ac. The crop was planted five months ago and received its first rain since then a few weeks ago. It stands 12-inches tall with an excellent wide leaf structure. Skip row sowing addresses two of the main issues in dry Prairie crop production, moisture and sunlight capture. The combination of improved solar capture creating larger more productive leaves with access to more moisture than a solid seeded field is a winning combination. As I learned in Australia and now in Kenya, an inexpensive tweak in your farming system could make a huge difference. SL
Morrin, Alberta gumbo in Athi River, Kenya
A lesson in vision
When fellow Nuffield Scholar Stuart Barden travelled through Athi River, Kenya a few years ago he saw something that most people didn’t and that was land with potential. On the surface you see short grass with thorny trees and what looks like a dry desert plain. Underneath that dry prairie plain is 2:1 cracking clay soil, high in organic matter and nutrient rich from millennia of short grass vegetation and wildlife grazing. Oddly enough, if you dig deeper you’ll find a soil type no different than the Morrin gumbo we farm across the planet.
In the top photo Stuart is standing in a soil pit dug for a field day he recently hosted. You’ll notice the black, heavy clay profile that reaches down three or four feet. The photo below shows Stuart’s boot beside a large crack in the soil. The swelling and contraction of the clay has allowed black soil high in organic matter to fall below the surface making it a very productive soil when managed properly. It’s rich in nutrients and has incredible moisture holding capacity, roughly 2-2.5 inches per foot under conventional no-till. Stuart tells me his sorghum crop saw its first shot of rain since seeding just 17 days ago, five months after planting! The leaves are just starting to senesce which is unbelievable and a testament to this soil type.
Kenya’s climate is known for its two wet seasons, each followed by a very dry season. The long wet season may drop 24 inches of rain followed by a three or four month dry season. The short wet season may bring 16 inches of rain. The majority of Kenya’s crop growing region sits above 5,000 ft above sea level, 1 degree south of the equator with very consistent temperatures in the low-teens at night and mid-twenties during the day. Cropping options are wide but many prefer wheat, barley, canola, peas and corn. Stuart is trialing desi and kabuli chickpeas, sorghum and soon enough flax.
The key to farming successfully in Kenya is to build a system that relies on stored soil moisture and not rainfall. Stuart is building his system to do exactly that by focusing on soil structure and row spacing techniques that utilize moisture efficiently. The bonus for Stuart is that he is starting with fresh breaking. He doesn’t have to deal with years of soil damage from equipment traffic and plow pan layers. Stuart has a unique opportunity to build a soil that has the ability to store incredible amounts of water at depth and allow plants to draw on that water during the dry season.
There is no doubt in my mind that Stuart is bang on the money. This soil type lies within an excellent climate and coupled with a well designed farming system has the potential to produce awesome yields. Here are my estimates on his potential yields:
Wheat: 115 bu/ac + (7.5 t/ha)
Barley: 145 bu/ac+ (7.8 t/ha)
Canola: 80 bu/ac + (4.5 t/ha)
Peas: 80 bu/ac + (5.4 t/ha)
The fact that Stuart saw the potential in this area and soil type is a real lesson in vision and belief in what can be accomplished. Still, it’s no easy feat and not for the faint of heart here in Kenya. SL
If you’re curious to know more about Stuart and his current endeavors he will be a keynote speaker at FarmTech in January 2013.
Three overlooked production factors
The most often ignored elements in crop production are carbon, hydrogen and oxygen. I believe these three elements alone hold the biggest key to unlocking higher yields in our production systems today. In fact, to give you an idea of their significance, with nothing limiting growth, a plant’s total dry matter will consist of 45% oxygen, 45% carbon and 6% hydrogen. Add these totals together and oxygen, carbon and hydrogen account for 96% of total plant dry matter. The other 4% consists of macro and micro nutrients with the next highest element concentration being nitrogen at a mere 1.5% followed by potassium at 1%, calcium at 0.5% and the rest fall under 0.2%.
It is important to understand how carbon, oxygen and hydrogen enter a plant before we get into disease-nutrient interactions as they form the structural components of all plant tissues.
Carbon and oxygen: The primary source of carbon and oxygen enter the plant as CO2 through leaf pores (stomata). Atmospheric oxygen also enters through the stomata. A third source of oxygen enters the plant through the root system via H2O or through the soil solution attached to nutrients like phosphorus and sulphate.
Hydrogen: The primary source of hydrogen comes from water H2O entering through the root system. Another source is through the soil solution attached to nutrients like phosphorus, ammonium and sulphate.
Did you know there are four ways to get oxygen inside a plant? Have you stopped to think of how hydrogen entered a plant? We can’t control the atmospheric concentration of CO2 short term, unless of course you’re Al Gore, and we can’t control the level of oxygen in the air. What we can alter are the levels of carbon, oxygen and hydrogen in our soils. We can manipulate root growth, carbon cycling, nutrient levels, water holding capacity, pore spaces and water infiltration rates. In doing so, I believe we can take yields to another level.
The adoption of zero-tillage or minimum disturbance seeding systems has elevated soil carbon levels, improved water infiltration rates, pore spaces, soil oxygen levels, nutrient cycling and ultimately boosted our yields. I believe that zero-tillage unlocked a portion of the carbon, hydrogen and water cycling we were missing under conventional farming practices. The downside of zero-tillage is the compression of our soil by heavier equipment, axle loads and higher slippage percentages. The result is a soil left with less oxygen and water holding capacity. If you remember oxygen and hydrogen make up 51% of plant dry matter so we had better make sure it’s not limiting.
Now, to unlock the next door we must focus our attention on soil structure by reducing the damaging effects of soil compaction. The fastest and most efficient way to improve soil structure is through controlled traffic farming. You can deep rip soil to improve drainage and soil structure somewhat but if you continue to drive randomly across the field, you’ll be back where you started within two years. I’ve seen firsthand what CTF can do to soil structure in just a few short years on our farm. Moisture reaches down the soil profile four feet within 24 hours and it’s now storing more moisture at depth. Water no longer ponds on the surface, it gets absorbed and stored for later use. Yields are well above area average and even our own average with no change to our agronomy program.
We all know what zero-till farming has done to nutrient and carbon cycling. Nutrients and carbon make up close to 50% of total plant dry matter and zero-till has increased the supply of both over time. Now it’s time to focus on the other 50% which is oxygen and hydrogen and see where yields can go as Mitch and I are experiencing using CTF. The key to unlock the door is soil structure and it’s time we pay closer attention to what’s below ground rather than what’s above. It’s time to jump off the zero till yield plateau we’ve been sitting on. SL
Beyond Agronomy Apple and Android Apps
I’m excited to announce the launch of our new smartphone apps for Apple and Android!
The seeding rate calculator app allows you to enter your desired plant density, thousand kernel weight, germination, seedling mortality and instantly provides the correct seeding rate in lbs/ac.
The herbicide tank mix and rainfast guide app tells you what order to mix each herbicide and how long you have until it rains. This quick and easy to use app is tailored to Western Canadian farmers.
These apps will make your life easier and who doesn’t need a little ease? Hop on over to www.beyondagronomy.com to get yours today. Then tell your friends!
