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The New Agriculture Network's on-line newsletter with seasonal advice for field crop and vegetable growers interested in organic agriculture.
Next issue will be posted October 10, 2007. Read previous issues through our calendar of issues. Transition practices and soil fertility Michelle Wander1, Carmen Ugarte1, and Ed Zaborski2; 1University of Illinois, Department of Natural Resources and Environmental Sciences (mwander@uiuc.edu). 2 Illinois Natural History Survey This article reports on changes in the soil in the Windsor Organic Research on Transition (WORT) study that have occurred as a result of three transition strategies. Our study team compared transition in a vegetable crop and row crop systems with transition under perennial pasture. These three strategies represent high (vegetable), intermediate (row crop) and low-input transition systems. Fertility was manipulated within these main treatments as called for by crop and soil management goals. |
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| When we designed the study, the high input treatment was meant to serve intensive vegetable crop growers that farm small acreages, include more crops and covers over time, and perform relatively frequent and aggressive tillage operations. The intermediate treatment was meant to reflect common practices of cash-grain farmers and should be relevant to large scale vegetable producers or folks mixing the two. We assumed that inputs and operations would be optimized to keep costs down during transition because grain farmers do not often benefit from organic premiums before certification. The low input or extensive-system reflects a strategy that is increasingly used by intensive vegetable growers and that is used by farmers with livestock or that market hay. Previous New Ag Network articles provide more information (see: http://www.ipm.msu.edu/new-ag/issues04/06-24.htm#3; http://www.new-ag.msu.edu/issues05/10-13.htm#3). We wanted to know how well high, intermediate and low input transition systems were able to satisfy NOP’s soil fertility and crop nutrient management practice standard (see box 1), which requires growers to improve the soil and protect the environment. If you are managing to minimize erosion and prevent water running off or on to the field, as is required, then changes in soil organic matter levels and soil test values can provide a good measure of management’s influence on soils. We found that the high, intermediate and low-input transition strategies used did not differ in their ability to build soils and that soil fertility was improved in all cases by conversion to organic management. Our use of straw mulch to control weeds in the intensive veggie system probably contributed to the success of that system. The only difference among systems observed was their ability to change soil pH; even though we did not apply lime during the study, pH was increased in the low input (pasture-based) scenario. This is likely due to the ability of perennial roots to capture nutrients in the subsoil and concentrate them in the rooting zone. Fertility sub-treatments did not significantly alter soil fertility status within any of the main treatments. More typically, addition of manures and composts increases nutrient stocks, in particular P and K, and values remain high for several years.
Table 1. The influence of organic transition on soil fertility; values are means from samples taken from the surface depth (0-6”) in the spring we began and again when we ended the transition process. Measures include soil organic carbon (SOC), carbon-to-nitrogen ratio (C/N), plant available phosphorus (Bray P1), potassium (K), soil pH, and extractable calcium (Ca), magnesium (Mg) and the calcium-to-magnesium ratio (CA/Mg).
y SAS Proc Mixed was used to evaluate to the effects of time, transition system and fertility treatment within systems on the measures summarized here. SAS lsmeans was used to compare values when differences were significant (p<.10 or smaller). Means within columns that are not followed by the same letter are considered different. In addition to small increases in soil organic matter (SOM= SOC X 1.7) we noted an increase in the carbon-to-nitrogen ratio (C/N), which serves as a measure of organic matter quality. Increases in the C/N, like the one we see here, are typical in successful organic systems when new practices have increased the amount of young, biologically and physically active organic matter. As is common when converting a conventionally managed field, soil fertility status measured by standard tests was in the medium to high range for all variables when transition began. Even though plots received little-to-no fertilizer additions, soil nutrient stocks increased during the study. The calcium-to-magnesium ratio, which is already above the 7.5 value recommended by many, increased under organic management. Important take-home messages are:
Research (Cathy Eastman, Darin Eastburn, John Masiunas) and outreach (Leslie Cooperband, Deborah Cavanaugh-Grant, Dan Anderson). |
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Grant funding program seeks innovative ideas for the farm and ranch The North Central Region Sustainable Agriculture Research and Education (NCR-SARE) Program is seeking innovative farmers or ranchers who want to implement a new, sustainable, idea to improve their operation. NCR-SARE is currently accepting applications for their 2007 Farmer Rancher grant program. |
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| Reports from organic growers Indiana West Central Indiana, Tippecanoe County – Kevin Cooley Over the past two weeks we have received an additional 3-plus inches of rain. Here in central Indiana that is a little more than the average summer total and possibly ending our long dry spell. Even with the 8-plus inches we received over the past 15 to 18 days, the soil is handling it well, drying quickly after the rains and allowing us to get field work done. Recently we transplanted our backlog of lettuce transplants and now we are back on schedule with seeding and transplanting that crop. We have planted numerous rows of radishes, lettuce mix, spinach, bok choi, mustard, peas for pea shoots and other small greens. Everything has come up in record time and is looking very good so far. Other field tasks that we have completed in the past two weeks include pulling the last of the bulb onions, getting started with hand weeding of our newest strawberry patch, mowing, trellising the fall raspberries and trying to get the last of the potatoes out of the ground. Last Thursday (Sept. 6) we worked a plot of ground that was green beans and sowed it to winter rye without incorporating the seed. With the perfect timing of the gentle rains, it all sprouted and was visible early Monday morning. Plans for the upcoming week include finishing the strawberry weeding, transplanting our first high tunnel lettuce for the winter season, starting work on tunnel windows for the upcoming colder temperatures, finishing the potatoes dig, and continuing to harvest crops for our weekly farmer’s markets and subscription families. Southeast Indiana, Decatur County – Gary Reding Our popcorn is mostly brown now with some green remaining. We will probably start harvest in a week or two. It must be down to 17 percent moisture to minimize any seed scuffing that would cause a reduction in popping volume. It is all standing great so far and we just hope to not get any severe weather with high winds. The soybeans we planted first are almost completely yellow and have lost about half their leaves. The later planted field is 80 percent yellow and just starting to lose some leaves now. This rain is too late for either of the plantings. The seed size will be smaller than normal, which should reduce yield below what was possible. They seem to be podded well and most pods have three beans in them, which is helpful. Our grass is starting to green up just a little after the rain on Friday and Saturday (Sept. 7-8). We have kept the cattle off during the drought in hopes of the flush after the rain. I am counting on that right now. Even our fescue went into full dormancy during the heat. We brought in some young doe-lings to complement the cattle and eat some weeds that would not be eaten by the cattle. They are cleaning up some iron weeds and multi-floral roses in our winter fescue pasture quite well. Next week we will finish artificially inseminating our cows and will attempt to run the goats with the cows from now on. I am still cleaning some popcorn for delivery and that is keeping us busy until harvest. South Central Indiana, Brown County – Dale Rhoads Leaves are falling off the trees now and are coloring. Drought has brought more deer into the fields and we are putting several strategies in place now including killing one deer, putting the dogs on them, some fencing and we’re going to try some repellant. We expect deer pressure to rise as cooler weather comes on. Late sweet corn that did not get watered produced 50 ears from 2,000 feet of row. Nearby conventional corn fields have a lot of stalks with no ears. Recent rain put 12 inches of water in the irrigation pond, which should be sufficient for the rest of the year without moving the pump into deeper water. Currently we are planting salad greens; weeding and more weeding of fall salad greens, putting in some cover crops as summer areas come out of production; and harvesting tomatoes, leeks and kales. In the next two weeks we will finish salad greens plantings, weeding, finish up summer crops and prepare ground for cover crops, fertilize and plant covers, and pull tomatoes out of greenhouse and prepare it for late fall salad crops and spinach. IllinoisNorthern Illinois, Kane County – David Campbell of Lily Lake Organic Farm Dry weather has returned to northern Illinois the past two weeks. Temperatures dropped down into the 40s this morning (Sept. 11) for the first time since this past spring. We are still playing catch up with hay making. We’ve put up 75 acres in the past two weeks with only 10 acres to go. In the next two weeks we will finish harvesting hay. West Central Illinois, Fulton County – Anne Patterson of Living Earth Farm Currently we are harvesting winter squash, leeks and arugula, and potatoes have been dug. We are still harvesting some summer crops: tomatoes, eggplant, peppers, beans, tomatillos, lettuce and herbs. This week will be the last week for summer squash and melons. We are still planting fall/early winter arugula, spinach, mesclun, winter salad mix—primarily mix of tatsoi, red Russian kale, mizuna, arugula and Tokyo Bekana. The raised beds have had all the summer crops cut and worked in. They are awaiting fall crops or fall cover crops to be planted. During the next two weeks we will finish the last planting of fall/winter crops; plant cover crops; complete harvest of winter squash, clear field and plant cover crop; put up another deer fence; sort through garlic for seed and remainder to sell direct; and work on field plans on paper in my office. QuestionI’m curious to know how others build and sustain restaurant accounts (Send responses to newagnet@msu.edu). West Suburban Chicago, Will County – Steve Tiwald of Green Earth Institute We haven’t received any rain for two-and-a-half weeks, except for less than one-quarter inch last night. We can use some rain again. The dampness of the August rainy period accelerated the spread of fungal diseases in the fields. Septoria leaf blight has denuded most of our tomato plants. Powdery mildew has taken most of our summer squash and winter squash plants. Even the rutabagas have a fungal disease; I have never had a problem with rutabagas before. This is Week 14 of the 20-week CSA harvest season, and we are still spending a lot of time and resources harvesting. In terms of field maintenance, the flea beetles decimated the leaves in the Swiss chard and the kale, so we cut these back radically and let new leaves form. That process meant no harvest for three weeks, but it worked—the leaves have grown back and will soon be ready for harvest. We will rotate where we grow vegetables next year, after having grown for two years in the current field. We have identified the general location for next year’s field, and now we have to measure and plot it out. Then we will mow the strips, spread lime, spade and then plant cover crops. We have a lot of work to do. Other – flooding in parts of Wisconsin and MinnesotaAs you may know, rains in August caused devastating flooding in southwest Wisconsin and southeast Minnesota. Several of our fellow organic farmers were affected. For example, one farm near Viroqua, Wis., got 26 inches of rain between Aug. 11-31, including 12 inches on Aug. 18-19; they suffered crop losses of $800,000. At least one farm is declaring bankruptcy. A 9-minute video about the devastation caused by the rains and flooding of August 2007 to Wisconsin and Minnesota organic produce farms is available on the web at http://web.mac.com/milhug/Downtown_Dailies/Flood_of_August_2007.html. Michigan East Michigan, Lapeer County – John Simmons Continued rains have supplied enough moisture to finish crop growth. Corn has good color and fields have completed pollination and are using the moisture for grain fill. Sunflower bloom is progressing to seed fill. Soybeans range from pod set to leaf drop. Hay re-growth has been accelerated by the recent moisture. Prospects look good for a third cut. Current haying efforts have been hampered by rains. No insect problems have been identified lately. Buckwheat is in full bloom and setting seeds. In the next two weeks, I will start harvest of clover seed and prepare fields for fall spelt and wheat planting. Southwest Michigan, Berrien County – Greg Vlaming of Maple Grove Organic Farm Ironically, as the season winds down, the chickens have really begun to lay the eggs, increasing their production by more than five times what we had been getting! We did increase their protein ration, and the cool weather near the Lake has been a help as well. Nonetheless, we still cannot keep up with the customer demand for our eggs. Many lessons here for next year as areas rotate out of production, cover crops are seeded. We also prepped our soil in the blueberry block. I spent a Friday afternoon (prior to market harvest) prepping the soil with elemental sulfur, fertilizer and Dairy Doo compost, tilling, then seeding the cover crop, all in a bit of a rush as rain was forecast. Well it rained alright; more than four inches floated much of the seed to the low end of the field. Needless to say, the stand looks a bit spotty – something I will get to enjoy until planting next spring. MinnesotaWestern Minnesota, Lac qui Parle County – Carmen Fernholz Weather patterns have been slowly shifting to the fall season with cooler nights and warm sunny days. The corn is fast moving to maturity and soybeans are well into leaf drop. I harvested a fourth cutting of alfalfa that was, in fact, larger than the third cutting. I also rotary mowed off the regrowth of the cover crop in the oats field as an additional source of nutrient for the 2008 crop. Winter wheat is all seeded and nicely emerged except for a few dry areas in the fields. The period from early to late September is sort of a holding pattern for grain farming activities. I will spend time readying the combine for harvest and the tillage and shredding equipment for final operations. |
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