Greetings – today we are tackling a question that was posed by Rich Nelson, chief strategist with Allendale, Inc. at their Ag Leaders Conference in late January.

Nelson asked the question to the conference audience of whether US soil moisture needs to be corrected in order to grow corn. He said, that’s what everybody in the industry is betting on – that we need to correct the three to nine inch water deficit in the western Corn Belt or it will impact yields.

To answer the question, Nelson took a look at history – looking at the correlation between weather and yields. When we talk about weather - normal temperatures and normal precipitation generally hits or exceeds trend yields and better-than-expected weather creates better-than-expected trend yields.

Looking at the year following poor weather conditions:

• In 1974, there was excess moisture. In 1975 the Midwest soil conditions recovered and the yield trend was -8%.
• In 1983,there was excess moisture in the West. In 1984, problems remained and the yield trend was +2%.
• After the 1988 severe drought, weather problems were fixed in the East but drought remained in the West. The yield trend was +3%.

Based on this data, Nelson said incoming soil moisture is not a key determinant of yields. He said each year’s temperature and moisture, meaning timely rainfall, are the main determinant of yields.

The 2012 western Corn Belt yield was 133.1 bu/A. Based on the current forecast, Allendale expects the western Corn Belt yield to be at 145 bu/A.

Nelson’s key concern is that growers don’t get caught up in the soil moisture trap. Given the data behind the last three major soil moisture years, he said the measure of yield growth had no relation to carryover moisture.

On a separate note… this week, I’m off to Johnston, Iowa, USA for the annual DuPont Pioneer media event – I’ll be sure to share insights next week.

Have a great week!