Soils - Eckerton Hill Farm
Posted: July 21, 2015
Tim Stark runs Eckerton Hill, a fifty-eight acre farm growing thirteen acres of vegetables every year. Their emphasis is on heirloom tomatoes which they sell through the New York City Greenmarket, to restaurants and through their growing CSA.
Soil Management Goals and Challenges
Tim works hard to improve the soil which is a well-drained somewhat shale type soil. His goals include increasing organic matter and providing sufficient nutrients, including micro-nutrients and calcium. This is only the fifth year on this recently purchased farm which had depleted soil which he is trying to improve by rotating his vegetables with hay, rye, oats and clover. Currently, the soil averages three percent organic matter.
At Eckerton Hill the main source of nitrogen is a cover crop of red clover grass hay seeded the fall after vegetables are grown. This hay cover crop is grown for two years (with one or two hay cuts per year). Then it is plowed down in the spring before vegetables are planted, or the fall before for early spring vegetables. Phosphorus and potassium come primarily from medium rates of compost applied the year before vegetables (only 1 time every 3 years). Rock phosphate and other organic granular amendments are sometimes added when needed, especially in high tunnels which have production every year.
Soil Tilth and Health
Tim is improving soil tilth on his farm by adding organic matter and reducing tillage. Perennial hay crops have deep roots which add organic matter deep into the soil and provide food for soil organisms which help the soil stick together in crumbly aggregates. When the clover/grass hay is plowed in it provides a lot of organic matter to the soil, helping to increase soil organic matter. Long rotations are key to Tim’s soil management. Resting the soil for two years between vegetable crops gives the soil a lot of time to recuperate from the intense tillage of a vegetable field. There are many fewer total passes across the field than in a system with vegetables every year. This rotation also helps manage plant diseases. Any tomato plant material which could have hosted disease has degraded by the time tomatoes are planted again.
In order to prepare the soil for vegetable crops first the cover crop is plowed under using a moldboard plow. This incorporates the large amount of green material into the soil. After waiting a few weeks, then the field is disked at least once. He tries to wait a week between disc passes for the cover crop to break down further. In order to have enough time to plant early tomatoes the initial plowing is done as soon as there is a dry spell in the spring. Depending on how well the cover crop is broken down and the soil is broken up they will either rototill to make a nice seed bed or go in directly with a plastic layer to make raised beds.
Red clover and grass hay are the main cover crop. They are planted in the fall ideally by mid- September. Clover planted too late in the fall might not be large enough to make it through the winter without winter-killing. Tim plants the cover crops with a seed drill with the clover and orchard grass in the small seed box at a rate of 8 lb per acre clover and 6-8 lb per acre orchard grass.
Sample Fertility Calculation
To give you an example of how Tim meets his fertility take a look at the chart on the next page. The nitrogen recommendation for his tomato crop was 50lb/A. Because nitrogen availability goes up and down based on microbes mineralizing it, most nitrogen recommendations are based on plant needs not what is in the soil. To get a better estimate we need to account for what nitrogen might be available from the organic matter, cover crops, compost etc. In this field the organic matter was 3%. Organic matter has about 20 lb of available nitrogen per % OM. Because the Penn State recommendation assumed only 2% OM, Tim gave himself a credit of 20 lb of N/A for the additional % OM he has. A good clover cover crop can have 120 lb/A of nitrogen in the plant material. But only about 40% of this nitrogen will be available the year after you plow it in. The clover hay cover crop in that field did not have a high percent of clover so he got a credit of only 25 lb of nitrogen/A. He applied compost at 36 yd/A (about 10 T/A) to meet his phosphorus needs.
|2012 Fertility levels
|Fertility Recommendation (lb/A)||lime||N||P2O5||K20|
|Nitrogen Credits (lb/A)|
|OM (20 lb per % over 2%)||20|
|Prior Legume Cover Crop||25|
|subtract the above from recommendations|
applied nutrients 2013
(analysis 6 N 3.2 P 7 K lb/yd3 at 10 Ton/A
or 36 yd/A)
Soil Test results from field 2Top 2012
Tomato leaf tissue testing showing amendment applications were accurate.
Farm Profiles are designed to give new producers ideas and advice from experienced producers. Individual products are mentioned as examples not as an endorsement.
Prepared by Tianna DuPont, Sustainable Agriculture Educator, Penn State Extension, 2013.