With all the soil health conversations of late I thought share a story that started in 1989. As it happens the farm where this took place was not here in this country but a friend of mine in Portugal. I believe it is still relevant today because we saw, over the course of 4-5 years a dramatic change in how these fields performed and for the same reasons we still talk about today. I’ll try the short version. Also keep in mind that these fields have been cultivated far longer than most in states. Possibly hundreds of years longer.
The first visit I pretty well diagnosed the issue. The complaint, the grower found he had to continually apply more fertilizer to maintain yields. The growing season is like the Midwest however no natural rainfall in summer ( or very little) so all irrigation. You would think sunshine every day and water when you needed it would be most farmers nirvana. More NPK and additional tillage passes were thought to be the fix. Anywhere from 4-7 tillage passes made on these fields depending on soil type and crop to be grown. The fertility program had grown to 300-150-150, which still achieved better than 170 on the average. Even with the subsidies back then, the fertilizer prices were a minimum 2 times more than here and the fuel prices were triple. Profit was almost insignificant.
When probing these fields and digging holes, 2 glaring problems stuck out like a sore thumb. No structure and no earthworms. The soil had become nothing more than an anchor. It was basically dead. And this was the norm!! We immediately began a proper soil testing program, assessed the planter and tillage equipment. We started liming, and reducing tillage dealing with what we had. A few years later we introduced strip till as the planters as set up could not handle residue well at all.
Life started to return to these fields. We brought back a fungi dominated soil to balance with more favorable conditions to bacteria as well. Our adjusted pH values and minimum till practices brought back structure to these fields. Earthworms started to return. In addition to better root growth, water movement a more biologically active soil, irrigation wells were tested and found to contain nitrogen levels that allowed for further reductions in Nitrogen application amounts. We still are not applying P to any extent. For a few years our fertilizer program went to 150-0-0 with even better yields.
The lesson learned is the same we are learning now. Better soil health leads to profitability and sustainability. It takes dedication and patience but the results are dramatic and undeniable.