Organic Farmer Network: Network Discussion Summary

Topic: Soil Health and Fertility

All Network participants agree that adding organic material is necessary.

Some in the Network use kelp for trace metals -- 1 lb/100 sq ft.

Some use Feather meal and KSO4.

Cathy uses KMag.

Some use pelleted composted chicken manure. Alvin is concerned about zinc and copper overloading when folks use lots of chicken litter. Ken says no one has told him how much is too much of those. Ken says layer house manure has too much Ca to be applied to blueberries. Need to look out for increase in pH when using poultry manures. Wiedigers use 1 ton/acre and Mark uses 40 lbs per 500 square feet on vegetables. He puts it in between spading and final tilling to prepare seed bed.

Need to do waste analysis report on that manure. It’s a different test for manure- waste test. This test indicates what’s immediately available from a manure.

Alvin uses foliar sprayed liquid seaweed, and uses cover crops. He will spray greens crops with LiquiCal once.

Ken applies 100 lb N/acre for most crops. For strawberries, potatoes, and broccoli, he applies150 lb/acre. For most flowers he applies 80 lb/acre. Then monitors. With his sandy soil, it can suddenly be out of N.

He uses Chilean nitrate as a supplement if a crop shows it needs it. This saves many crops. With peppers, for example, he always has trouble maintaining N needs throughout the season. He gives Chilean nitrate in late August and gets lots more fruit to pick. Puts it in the irrigation water -- as little as 5 lb/acre. Organic certification standards, allow producers to apply Chilean nitrate up to 20% of the N given to a crop.

Alvin gets the same results from seaweed, though not as fast. Ken didn’t see much results from seaweed or kelp as a foliar spray.

Ken feels that you can’t build up soil fertility fast enough with cover crops if starting with worn out soil. For example, rock phosphate is available very slowly. After building soil up, cover crops will go a long way. Also if the soil is way out of balance, can balance it fast enough with compost or compost tea.

Ellen says making good compost and growing cover crops is what she does for soil health and fertility. It is the long-term answer. You must build soil life. You add microbes through compost. The microbes are the answer. The plants know how to do the math every time. Must have the microbes in the soil!
With compost you don’t have to worry about the details of fertility and don’t need to know about mineral balancing. Ellen uses 5 tons of compost per acre minimum application rate.

Need to make the distinction about properly made compost and improperly made compost. Also need to watch out for contaminants. The herbicide clopyralid survives the compost process. It will kill your crop and you can’t grow on that ground for 3 years. One farmer Network members know killed several vegetable crops because of composting horse manure to compost that had been contaminated through grain/hay feed sprayed with this herbicide. Apparently many large scale hay makers will spray hay with herbcides to kill them and dry them on the stem and then cut and bale right away.

Spray on compost tea is another option.

Tim will save rainwater and stir 50 strokes one way and then the other. Feels it enhances absorption of the water by the soil. Paul says Biodynamic preps call for stirring one way and then the next. He sees why now after having worked in the ceramics industry. It is breaking the vortex created by stirring, by stirring the other way.

Tim applies woodchips to trenches and lets them decompose for 2 years. Then uses the decomposed woodchips on his plants. Also applies bloodmeal for N.

Ken notes relationship between soil health and plant disease: “I put up a new 30x95 tunnel this winter. A year ago the site was growing trees. Stumps pushed out in September. In the fall I spread a heavy application of aged cow manure, aged chicken manure and lime on the site. My intent was to get the frame up and covered before winter so it would stay warm and the microbial population, in response to the manure dinner, begin to shift from fungal dominated woodland soil, to bacterial dominated soil more suitable to vegetable production. All the rain actually prevented me from getting the house covered til March, and I was concerned that much of the nutrients from the manure had leached out, so when I was finally able to til and plant I also applied feather meal at about 50 # N per acre, sulphate of potash the same, plus a 50 bag of Kelp meal in the house, and 300 # of greensand. I planted tomatoes and cukes. Tomatoes have grown great from the get go. There are 4 varieties of cukes - Jazzer, Tasty Jade, Genuine, and Diva. Many of the Divas died quickly and early on just after that week when it rained and was cold for 5 days. I sent sample's to the NCDA lab and they said there was Pithium and that the soluble salts in the sol were very high (no surprise) and that high salts made plants more susceptible to Pithium. Since then, no more plants have died, the tomatoes and cukes are blooming. I have been drip watering often. The connection between Pithium and high salts made me wonder how many ‘disease’ problems are related to management practices. Backs up that well-known notion that good well balanced organic management results in healthier plants that are less prone to disease.”

Cathy wants to know how the Network participants use soil tests. She notes that difference sources give different crop nutrient requirements. But she sends soil samples to be tested to NC State lab.

Ellen responds: “I don't believe in fertilizing a crop, but in improving overall soil health. So I don't pay any attention to specific nutrient requirements…I'm not a big believer in soil testing and haven't done any for over 5 years.”

Ken responds “As it is a certification requirement, I do soil test annually. I think it is a good idea as a monitoring tool more than a tool for determining nutrient application to specific crops.” By watching trends, he can make decisions about improving the soil. He says he used to use poultry litter at high rates but didn’t realize how far he was getting his pH up- over 7! This ties up nutrients. He had gotten his P and Ca up way high too. He stopped using chicken litter.

Charlie says soil testing helped him learn, with the help of Mark Schonbeck, that low boron explains why he can’t grow beets. This also causes corkiness around stems of tomatoes and hollow stems on brassicas.

Paul doesn’t trust the reliability of soil tests.

Seven out of the ten Network participants soil test.

Tim wants to know what “glowing” material is in soil: “Over the years of digging late at night here in Texas I come across a material that glows at night time when exposed to the surface.  The material is usually connected in stands of 2-10 pieces the size of a pinhead.  When the temp is just right a bed 4-6 feet wide by 75 feet long tilled at night the bed would be glowing when exposed from a late night tilling.”

Ken responds: “There are numerous phosphorescent fungi. I have seen glowing stuff in rotten logs, leaf mold etc. Would suspect what you are seeing is similar.” He speculates it comes from all the woodchips Tim uses.