Agronomist Notes

Just one week back in the country and I had a convenient opportunity to take in a farm sale. It’s great to be back and visit with clients and acquaintances after two months of being away. I have a funny story to share about that auction. There were several 5,000 bushel bins up for bid and out of a crowd of 300 farmers the only people bidding happened to be my clients. While everyone else was looking to buy iron, my clients were in need of more bin space. That’s a feel good moment for a crop advisor!

This week we’ll discuss the difficult subject of seedling mortality and how much to account for. I’ll provide some rules of thumb I use and where I see the highest mortalities. We’ll also talk about adjusting seeding rates on the go and last year’s success with that. Lastly, we’ll look at why late seeding is detrimental to yield. Have a great week.

Agronomy

Estimating Seedling Mortality – Not a Simple Task
The most difficult part of calculating seeding rates is trying to determine the correct seedling mortality. Many industry professionals use a safe baseline of 20% mortality in cereals and 50% mortality in canola. Although safe, you can sometimes end up with heavy plant stand densities which increase lodging potential or thin kernels from heavy crop competition. So where’s the balance? In a perfect world, we would have a calculator that included scores for seeding date, moisture, soil temperature, soil texture, crop rotation, residue cover, insect and disease history, seed lot vigour, openers, fertilizer placement, and seedbed utilization— just to name a few. However, we don’t have such a tool.

Ideally, seedling mortality should be calculated the day of seeding while including all the factors listed above. Since very few people have time to do that I’ll share some rules of thumb I use when determining seedling mortality. Listed below, you’ll find my average rule of thumb for estimating seedling mortality for the fields I work with. By no means scientific, the numbers are simple averages across the fields I’ve managed over the last five years. Take them as a reference point for when and where I find increased seedling mortality.

Clay Soils
Soil temp less than 5 0C Seeding date before May 1
Mortality: 20%

Soil temp higher than 5 0C
Seeding date after May 1
Mortality: 15%

Clay Loam Soils
Soil temp less than 5 0C
Seeding date before May 1
Mortality: 15%

Soil temp higher than 5 0C
Seeding date after May 1
Mortality: 10%

Loam to Sandy Loam Soils
Soil temp less than 5 0C
Seeding date before May 1
Mortality: 12%

Soil temp higher than 5 0C
Seeding date after May 1
Mortality: 7%

In the following example I’ve used 12lbs/ac in saved seed costs by knowing my seedling mortality is 10% lower than the 20% industry baseline. That is 120 lbs/ac seeding rate × 10% = 12 lbs/ac less seed. We’ll assume that achieving optimum plant stand density will provide a return as well. 

Example: (3,000 ac × 12 lbs/ac seed ÷ 60 lbs/bu × $7.00/bu) + (600 bu × $2.40/bu seed treatment) = $5,640.00

The only way to begin understanding mortality rates on your own farm is to begin measuring. The return on your investment is worth it. SL

Adjusting Seeding Rates on the Go – A Success Story
To give you an example of adjusting seeding rates on the fly, last year I suggested a client bump his wheat seeding rate by 18% towards the end of May. We were still seeding HRS wheat by the end of May and beginning of June and were getting concerned about maturity. At that time I felt there was more than enough moisture in the soil to carry a 50 bushel wheat crop, barring any hot spells. The wheat fields we increased the rate on yielded a few bushels more and matured the same time as fields seeded 10 days earlier with normal seeding rates. It was the right decision at the time and with very little risk. If you haven’t used a seeding rate calculator before, this is the standard:

Seeding rate (lb/ac) = desired plant population/ft² × 1,000 K wt. (g) ÷ seedling survival rate (in decimal form such as 0.90) ÷ 10.4

For more information go to http://www.agric.gov.ab.ca/app19/loadSeedRateCalc. SL

Late Seeding and Reduced Yield 
In many areas across Western Canada, if seeding is delayed past May 15 we can expect a 1% reduction in yield for each day planting is delayed. Some farmers will say you lose a bushel per day after May 15. The main factor contributing to yield reduction after delayed seeding is the potential for higher temperatures during the 4 to 5 leaf stage. This is the growth stage when the number of kernels per head is determined. The number of kernels per head decreases whenever the maximum day temperatures climb above 170C during this specific growth stage, which is usually during the second week of June. In years when June and early July temperatures do not exceed 250 C, yield reductions due to late planting will not be as significant.

This is one of the reasons “pop-up” fertilizer like seed-placed phosphorus is so important. My clients apply phosphorus right with the seed to maximize uptake efficiency. I find this system works very well, especially on high pH, low phosphorus soils. This system fires seeds out of the ground quickly and helps our plants to begin their critical yield setting stage before the heat sets in June. SL 
Reference: NDSU

Market News

Purchase Phosphorus This Spring for 2009
It sounds ridiculous but if you do the math, purchasing 2009’s phosphorus requirements this spring may be a profitable venture. I realize I’m speculating that fertilizer prices will go up. With demand for food increasing and world grain ending stocks at an all time low, the probability of fertilizer prices decreasing are very slim. Added to that, expensive oil and shipping costs will force imported fertilizer prices upwards. Phosphorus is a non-renewable resource in precious demand around the world. Prices are expected to move to the $1,250 to $1,500 a tonne levels in the UK and Australia. Something tells me we won’t be far behind.

Let’s do the math on purchasing 100 tonnes of 11-52-0-0 in 2008 for a 4,000 acre farm:
100 tonne × $1,000/tonne = $100,000
$100,000 × 8% interest = $8,000
Total cost of purchase = $108,000

Next, let’s calculate the cost for the same farm with a possible 2009 price:
100 tonne x $1,500/tonne = $150,000
Total cost of purchase = $150,000

You could potentially save $42,000 ($150,000 - $108,000 = $42,000) after interest costs by purchasing your 2009 phosphorus fertilizer requirements this spring. You could even add some storage costs for the fertilizer dealer to store it until next fall or winter and still be ahead $40,000. Food for thought. SL

Rains Damage 100,000 Ha of Wheat In Northern India
Wheat crops in around 100,000 hectares of land may have been damaged in India’s key growing province of Haryana after recent rains and hailstorms. Heavy rains and hailstorms lashed several parts of Northern India over the weekend, which produces more than 90% of the country’s annual wheat output.
Source: CBOT News

What Crop to Swing Your Optional Acres
With two inches of moisture in the ground this spring and barley prices climbing we need to re-evaluate what crops to plant in our optional fields—the ones  we could seed to barley, wheat or canola without sacrificing crop rotation.

If we were to get six inches of moisture we have the potential to produce:
64 bu/ac barley (2 inches soil moisture + 6 inches rain × 8 bu/inch)
48 bu/ac wheat (2 inches soil moisture + 6 inches rain × 6 bu/inch)
32 bu/ac canola (2 inches soil moisture + 6 inches rain × 4 bu/inch)

Using $7.00/bu wheat, $4.50/bu barley and $11.00/bu canola we have a potential gross return of $336, $288 and $384, respectively. Canola still stands out well but a lot can happen between now and the end of April. SL

The Probability of Trend Yields Around The World
There is a great deal of talk about world supply increases in corn, soybeans and wheat based on each country producing trend yields. Is that a realistic goal? Let me paint a picture for you. Our good friends in Australia have had a little moisture this spring after years of drought but haven’t even begun seeding. India, the world’s second largest wheat producer, had 100,000 hectares damaged by wind, hail and heavy rains over the weekend with damage estimates yet to be determined. The US is dry in the western wheat growing plains while the mid-west has excessive moisture. Indiana and Kentucky wheat areas have gone from drought to flooding causing damage to winter wheat. The Dakotas and Western Canada have low subsoil moisture going into spring. China, Russia and the Ukraine were dry last year and could be once again this year. So, after painting that small picture do you still think it’s reasonable to estimate world supply based on global trend yields occurring? I don’t! SL