Agronomist Notes
Finally, harvest is complete for roughly 98% of producers out there. Thankfully we’ve avoided the snow and this week we might be able to speed over those gnarly residue fields with the heavy harrow. Some producers are still fall banding and some are applying Edge, Fortress and Avadex.
The only other field work left may be to fall apply sulphur if it pencils out. I’m not so keen on pushing the post-harvest window at this point and suggest we shut down the sprayers for this year. I usually have all my soil sampling completed by now, but alas, I will start this week and hope for a good stretch of weather to get it finished.
In this week’s newsletter we’ll go over the numbers to see if fall applying sulphur makes sense. We’ll also look at balancing nitrogen to sulphur ratios in cereals and oilseeds and then conclude with international crop weather news. Have a great week.
Agronomy
Does a fall application of sulphur make economic sense?
Over the last few years, many producers have applied ammonium sulphate fines (21-0-0-24) in the fall as a means of speeding up seeding in the spring. And, at $320 a tonne, it made a lot of economic and agronomic sense. I recommended it on about 4,500 acres of canola last year. We commonly apply about 100 lbs per acre, which gives us 24 lbs of sulphur and 21 lbs of nitrogen.
The biggest risk with broadcasting sulphate fines is the potential movement of sulphate off target after high rainfall events or quick snow melt run-off. The risk of nitrogen moving off target is low because a) it’s positively charged and quickly binds itself to negatively charged organic matter and clay particles, and b) we’re applying it during cool fall weather so nitrogen conversion and potential volatilization is reduced significantly.
This year, the price of ammonium sulphate fines is $529 a tonne and the cost of application is $7.00 an acre. As I see it, we have three options: 1) broadcast ammonium sulphate fines this fall, 2) apply T-90 elemental sulphur this fall or, 3) apply regular ammonium sulphate in a blend at seeding. Let’s run the numbers to see what makes sense.
In this example, we’ll use a 90-20-0-24 blend applied at 278 lbs an acre which costs $100.54 an acre. I know, it sounds ridiculous but its reality! Here’s a breakdown of the approximate costs for each nutrient source:
Urea nitrogen: $0.79/lb
Phosphate: $1.08/lb
Ammonium sulphate fines: $0.31/lb
Regular ammonium sulphate: $0.39/lb
Elemental T-90CR sulphur: $0.35/lb
Broadcast application: $7.00/ac
Option 1: Broadcast 100 lbs an acre of ammonium sulphate fines.
Broadcast application costs are $7.00 an acre with a fertilizer cost of $24.00 an acre. This includes 24 lbs of sulphur and 21 lbs of nitrogen. The total cost is $31.00 an acre and removes 100 lbs of product from your spring fertilizer blend. A 69-20-0-0 blend would be applied at seeding with a cost of $73.83 an acre. The total cost of fall broadcasting sulphate fines plus the spring fertilizer blend is $104.83 an acre.
Option 2: Broadcast 100 lbs of T-90 elemental sulphur and amortize over two canola crops.
Broadcast application costs are $7.00 an acre with a fertilizer cost of $31.50 an acre for a total of $38.50 an acre. This includes 90 lbs of sulphur to be amortized over two canola crops. A rotation that includes canola-wheat-wheat-barley-canola at 50 bu/ac, 60 bu/ac, 60 bu/ac, 100 bu/ac, 50 bu/ac respectively will uptake 104 lbs of sulphur over 5 years and remove only 52 lbs an acre. The total cost of fall broadcasting T-90 elemental sulphur plus the spring fertilizer blend (90-20-0-0) is $128.89 an acre. However, you could amortize the cost of the sulphur over two canola crops, so $19.25 + $90.39 is $109.64 an acre.
Option 3: Blend regular ammonium sulphate and apply at seeding.
The total cost of applying regular ammonium sulphate at seeding in a complete blend of 90-20-0-24 at 278 lbs an acre is $100.54.
I’m limited by time and space in this newsletter to run through all the possible scenarios. If you’re looking at price per pound, ammonium sulphate fines are still the most reasonably priced. Tack on floating charges and the regular ammonium sulphate applied at seeding becomes more economical. If we compare seeding efficiencies in the spring, ammonium sulphate fines give you the highest seeded acres per tank. For example, a 435 bushel tank (middle 102 bu, back 186 bu) using Option 3 and the full spring blend, you would get 56 acres per fill. If you use Option 1, you could increase your seeded acres by 31 acres to 87 acres per fill. For those speed demons pushing equipment efficiencies, the extra $4.29 per acre might be worth the added cost. However you slice it, I’ll leave it up to you to decide what works best on your farm. SL
Balancing nitrogen to sulphur ratios in cereals and canola
Balancing nitrogen with sulphur is an integral part of achieving maximum yield in both cereal crops and oilseeds. The ratio of N:S is significant because nitrogen can only be taken up at the rate to which sulphur is available and protein formation from sulphur is limited to the availability of nitrogen. With that, it is plausible to have a nitrogen deficiency in a high nitrogen soil if sulphur levels aren’t balanced properly.
Research done by Stewart et al in 1966 (SSSA 1966) on wheat straw with a low sulfur content was incorporated into soil fertilized with N, P and K and N, P, K and S. The plots had increasing amounts of straw incorporated into the soil and winter wheat was planted on these soils. The addition of wheat straw in increasing amounts to the soil to which no sulfur was added progressively decreased the growth of the wheat plants. The addition of sulfur in the fertilizer overcame the limiting effect of the straw.
As simple as it sounds to create fertility recommendations that balance N:S ratios, it’s actually quite difficult to put into practice. To show you why, let’s look at an example of nitrogen and sulphur levels across one of my variable rate fields in which we zoned out six production areas based on NDVI imagery.
The chart above shows a perfect example of how sulphur can vary across a field. We have a low of 16 lbs in Zone 1 at the 0-24 inch depth and up to 1,231 lbs an acre in Zone 4. So, from a soil fertility standpoint, it's really difficult if not impossible to balance N:S ratios to get the preferable 10:1 ratio in wheat for example or a 7:1 ratio in canola using a blanket fertilizer application.
Most of us will apply 15 to 25 lbs of sulphur each year on our canola as an insurance policy to protect against a potential deficiency. Factoring in the $7.00 to $10.00 cost of sulphur on each acre, knowing where sulphur is limiting and excessive could put money in your pocket from both fertilizer savings and increased yield potential. In the table above, by using variable rate technology, we wouldn't have to apply sulphur in 81 acres of the 217 acre field. At $10.00 an acre, that's $810.00 we could allocate elsewhere to help improve production potential.
The more I work with variable rate technology, the more I see opportunities for improving our crop production and theseeach year because we know that sulphur is highly variable anI believe that with today's variable rate technology, we canget closer to achieving balanced N:S ratios and improve yield, protein and quality. SL
Reference: A & L Labs
Market News
Wheat, Durum Values Lower While Malting Barley Unchanged in CWB 2008-09 PRO
The CWB released its October Pool Return Outlook (PRO) for the 2008-09 crop year. Milling wheat values declined $24 per tonne from the September PRO, while milling durum values are down $37. Feed barley is down $5 and designated barley remains unchanged from the mid-October PRO. The decline in the Canadian dollar has helped support all four pool return outlooks, as has a dramatic drop in ocean freight rates. The Canadian dollar is at its lowest levels in four years and ocean freight rates are now approaching six year lows.
The uncertainty and concern in financial, equity and commodity markets continues to impact the buying behaviour of grain customers. In general, grain processors are attempting to reduce risk exposure. In the short term, this results in reduced inventories, hand-to-mouth purchasing and delays in capital investments. Weaker demand at a time of record world wheat supply is an underlying factor in the dramatic declines we have seen in grain market prices. In the current environment of global economic uncertainty, grain market price volatility has the potential to continue to significantly impact forecast pool returns.
CWB PRO: http://www.cwb.ca/db/contracts/pool_return/pro.nsf/WebPRIndex?ReadForm&CropYr=2008-09
Source: http://www.cwb.ca/public/en
International Crop Weather News
United States: In the Northwest, dryness remains a concern with respect to winter wheat establishment. On the Plains, cool, dry weather is slowing winter wheat development, although soil moisture remains nearly ideal in most areas. Low temperatures ranged from below 15 degrees F across parts of the northern High Plains to near the freezing mark (32 degrees F) on the southern High Plains. In the Corn Belt, windy weather and scattered rain and snow showers accompany a surge of cold air. Summer crop harvesting continues as conditions permit, while winter wheat is benefiting from last week’s soil moisture improvements—although more rain is needed in the Ohio Valley. In the South, cool, windy weather prevails. Fieldwork includes winter wheat planting and soybean harvesting.
Europe: Showers across most of Europe slow summer crop harvesting and winter crop planting but maintain abundant moisture supplies for winter wheat and rapeseed establishment. Drier weather in the Balkans favors winter wheat planting.
Former Soviet Union: In Ukraine and western Russia, several days of unseasonably warm, dry weather favor corn, sunflower, and sugar beet harvesting and late-season winter grain planting. In eastern spring wheat areas of Russia, showery weather slows final harvest efforts.
East Asia: Warm, dry weather throughout China aids winter wheat and rapeseed planting.
Middle East: Showers return to Turkey, slowing fieldwork but benefiting emerging winter grains.
Northwest Africa: Rainy weather continues, providing favorable moisture for winter grain planting.
Australia: In eastern Australia, showers continue to benefit filling wheat and aid early summer crop development. In South Australia and Victoria, persistent dryness steadily reduces the yield potential of filling grains. In Western Australia, dry weather further reduces moisture supplies for filling winter grains.
South Africa: Rain boosts topsoil moisture for germination of corn and other summer crops.
South America: In Argentina, moderate to heavy rain benefits immature winter grains and improves planting prospects of summer grains and oilseeds. Warm, mostly dry weather promotes soybean planting in key growing areas of central Brazil. Heavy rain raises concern about the potential for damage to maturing winter wheat in Rio Grande do Sul.
Canada: Rain and snow showers delay the late stages of the spring grain and oilseed harvesting.
Mexico: Heavy rain boosts reservoir levels across the north and in winter farming areas of Veracruz.
