Over the next few days I will prepare the soil on our farm for the 2011 growing season. This means spreading and tilling in 50,000 lbs of composted horse manure, laying out beds, and doing some early season planting. Thankfully I have this handy John Deere tractor to handle the heavy tasks.
The Ice Storm
In early 2002 we moved from Raleigh to just outside of Chapel Hill to a house built on an all-wooded, ten acre lot. We certainly had no intention of farming at that time. Within that ten acres, four acres were in a dense pine forest (we cleared one acre for our house).
Unfortunately, in December 2002 a major ice storm decimated the remaining three acres of pines by breaking off the tops of one-half of the trees. According to a state forester, our pines were 45-50 years old and had never been thinned. Due to the overcrowding, these trees were spindly and had not grown much in the prior 20 years.
Rather than live with the eyesore (and the potential fire danger) of the topped trees, we had a small team of loggers clear the usable timber. Given my transition from software CEO to new dad of twin boys, I was eager to have a project that kept me close to home. The plan would be to turn those three acres of cleared land into a small farm. We would have one acre in cultivation, one acre in pasture, and the remaining land would eventually hold a small pond and a barn.
Dirt: The Nitty, Gritty Details
Generally, if you see a stand of pine trees in the eastern US, you can be pretty confident of a few things: the soil was previously farmed, is highly acidic, and is devoid of most key nutrients. Based on the results of a free soil test available from our county agriculture extension office, I was able to confirm that our cleared land would likely not grow a single weed, much less the bounty of vegetables I had imagined.
For starters, there was no topsoil. The soil was all yellow clay and hard as a brick. The pH measured 5.0 (extremely acidic) and there was no measurable phosphorus (critical for strong root development), little if any nitrogen, and zero organic matter.
Since the summer of 2004, I have spent many hours turning that clay soil into something capable of growing nutritious vegetables. I spread 3000 lbs of lime to improve the pH (it worked – pH is now 6.7). I put 1000 lbs of rock phosphate out which would release slowly over the coming 5-7 years. With the addition of chicken manure, I felt like I had my phosphorus needs covered. Lastly I spread 30,000 lbs of rock quarry gravel dust to provide trace minerals that may have been absent from the soil.
Following those initial preparations, I have applied 150,000 lbs of composted horse manure (over five growing seasons). This compost provided necessary nitrogen as well as organic matter which improved the texture of the soil. In addition, I have grown a cover crop each year. By growing a cover crop during times that I wasn’t growing vegetables, I was able to produce “free” organic matter that was then tilled back into the soil. And when available, I have taken advantage of free leaves from the town of Chapel Hill to use as mulch.
Current Soil Quality
I am finally working with soil that is usable. The soil drains well, is pH neutral, and has a significant amount of organic matter which allows plant roots to weave their way through. Probably the most significant change has been the return of earthworms to the farm. While they aren’t yet abundant, they are making an ongoing positive impact to the soil by opening it up and moving nutrients around.
Ideally I would have started farming on land that was in better condition. And had I not been in such a rush to grow vegetables immediately, I could have produced productive soil much quicker. Spending a year focused on hauling in massive amounts of organic matter followed by a year of cover cropping would have created the same soil I have today, only sooner. Lesson learned.