Organic Crop Meeting Focuses on Tillage, Pest Management Practices
Posted: June 6, 2011
Dave Johnson shows his Kovar coil tine weeder at a farm tour in 2010. Johnson spoke at the Central Susquehanna Valley Organic Crop Growers Network meeting in March.
Without the ability to use herbicides for weed management, organic farmers rely heavily on tillage for weed and residue management. In both conventional and organic systems, some negative consequences of frequent, intensive tillage can include loss of organic matter, increased soil strength, reduced infiltration rates, compaction, and increased risk for erosion. However, when considering soil organic matter and soil structure, there is recent research-based evidence that organic farming systems typically perform as well or better than conventional, herbicide-intensive systems with less soil disturbance. This is due to the use of high organic-matter inputs such as manures and composts, and crop rotations that include cover crops and perennial forages that can offset the negative influences of tillage on soil structure and organic matter.
Network members Abram “Bucky” Ziegler of Paradise Valley Organic Farm in Milton, Dave Johnson of Provident Farms in Liberty, PA, and Kit Kelly of White Frost Farm in Washingtonville, brought presentations about their farms and tillage and pest management practices to share with others and stimulate discussion.
Abram “Bucky” Ziegler and his wife Sherry began transitioning their farm to organic in 1997. During the droughty summers in the 1990’s he discovered that the soil was low in moisture holding organic matter because of a low diversity crop rotation of corn and soybean. To help build organic matter, Bucky incorporated cover crops into his rotation, and has begun experimenting with managing cover crops with a roller/crimper to reduce tillage. He’s just started, and has found that timing of cover crop management is critical – he felt that he was a little late last year. He also will be working out some of the challenges he had in planting soybeans through the heavy mat of residue that resulted from rolling a rye cover crop, which had been planted at 3.25 – 4 bu/acre on September 1. Bucky felt that last year, rye used up too much soil moisture during a very dry May and caused the ground to be hard, which added to planting difficulties in the rolled rye. His tilled beans, which were planted later, on June 20, yielded better than the beans planted into rolled rye on May 20. His soybean planting rate was 170,000/acre. Bucky is also planning on experimenting with planting corn into a rolled rye/winter pea cover crop.
In rotations using conventional tillage, Bucky frost seeds red clover into wheat. He clips the clover once in August or September, which stimulates lush growth. The following spring he uses a 4-bottom moldboard plow to till in the clover when it is about 1 ft tall. He also uses hairy vetch as a nitrogen-fixing cover crop, but is careful to manage it to prevent seed production that may cause problems later in small grains. He plants the vetch with a nurse crop of oats (25 lbs vetch to1 bu oats) in late August or early September, and plows the vetch under the following mid-May before it flowers. Corn is planted at 26,000/acre. Bucky is also interested in trying to underseed ryegrass into corn with a Vicon seeder at the last cultivation for Fall grazing of beef cattle on the ryegrass and corn stalks.
For weed control in corn, Bucky’s cultivation practices include blind cultivation with a Kovar tine harrow five days after planting, and then again five days later. He has found that the tine weeder is ineffective on soil that has crusted – in those conditions he prefers a rotary hoe. In soybeans, he uses the tine weeder, but only once, two to three days after planting to avoid pulling the seedlings out of the ground. Bucky uses a C-tine cultivator with three tines/row later in the season, and would like to try an S-tine cultivator. For Canada thistle control, he likes to use a moldboard plow to a depth of 8 to 9 inches when the weather is hot and dry to kill the rhizomes exposed on the soil surface. He also finds that sorghum-sudan, which he feeds to dry cows, followed by alfalfa helps to suppress Canada thistle.
Dave Johnson shared information about the field crop operations at Provident Farms in Liberty, PA. Provident Farm is an organic, grass-based, and diversified farm. Their seasonal dairy is complimented by pastured poultry, eggs, pork, and beef sold to restaurants and retail. Provident Farm’s enterprises have included direct marketing of pastured beef, poultry and pork, in addition to a current focus on the seasonal grass-based dairy. Johnson describes Provident Farm’s topography in Pennsylvania’s northern tier as “grass and clover country.” When organic grain prices peaked a couple of years ago, the farm added corn, oilseed and small grain production to complement their forages. Dave also serves as a Northeast Sustainable Agriculture Research and Education (NESARE) farmer educator, and has served on the boards of the Northeast Organic Dairy Producers Association (NODPA) and the Pennsylvania Association for Sustainable Agriculture.
Dave focused on his soil management practices in row crops and small grains for weed control. Dave uses a 4-bottom Kverneland plow, pulled at 5 to 8 mph for primary tillage. The moldboard is very long and doesn’t throw the soil, but lays it over, leaving the soil surface relatively smooth without deep plow furrows. On new ground, he plows 10 to 12 inches deep, otherwise he sets the plow to 8 to 10 inches. For weed control, Dave uses a Kovar coil tine weeder in small grains and corn a few days after planting, when plants are 3 to 5 inches tall, and again when plants are 10 to 12 inches tall. Dave’s advice when using a tine weeder is to “use a small tractor, drive like mad, and don’t look back!” After the crops are up, he uses a Brillion 4 row crop cultivator with S-tines with 3 inter-row tines with a wide duck-tooth on the center tine with the two outer tines a little narrower. For uneven ground, Dave likes the Brillion because the tines float individually. He likes the S-tine because he can travel fast without throwing a lot of soil up onto the plants. Because he plants on hilly ground, he uses 36 inch rows.
Kit Kelly shared information about the crop mix and management at White Frost Farm. Kit and his wife Cathy grow and direct market a variety of vegetables, pastured poultry and eggs. They recently planted an apple orchard to help diversify their farm. The Kelly’s grow a variety of cover crops, including medium red clover, rye, oats, and buckwheat to manage soil fertility. In 2007, they harvested their first wheat crop. They direct market both wheat berries and whole wheat flour. They feel small grains have a bright future in small farm diversification. In their hard winter wheat trials they intend to find the varieties of wheat best suited to their soils to produce quality flour with the rich flavors and textures desired by local bakers.
The Kelly’s have been very active in conducting research on their farm. Similar to many organic vegetable growers, the Kelly’s are challenged by insect pests in cucurbits. Cucurbit pests are especially challenging to organic growers, who have few cost-effective, allowable insect control materials available. In 2008, the Kelly’s hosted an on-farm research project to produce butternut squash in a hoop house covered with Proteknetr (Dubois Agrinovation) anti-insect screening to create a physical barrier to squash bugs and cucumber beetles. The anti-insect screen material is manufactured with clear high density polyethylene with an estimated lifespan 8 to 10 years. This material has no thermal effect, so it can be laid during summer time, and also protects crops against weather damage. Purchased bumblebees were used to provide pollination of the cucurbits in the hoop house. The Kelly’s had previously tried to use floating row cover to protect their cucurbits from insects, but found that it was too warm under the row cover for good pollinator activity.
The local, heritage, organic food movement has created increased interest by millers, bakers and consumers in regionally-grown and processed heritage wheat. Kit and Cathy became involved in a hard red winter wheat trial in collaboration with Elizabeth Dyck, NY Organic Growers’ Research and Information-Sharing Network. The Kelly’s have tested the performance of the varieties AC Morley, Red Fife, Maxine, Warthog, and Arapaho. Yields in the 2009 test ranged from 53 to 59 bu/A. They hosted a cooperative NOFA-NY/PASA (Pennsylvania Association for Sustainable Agriculture) field day in July 2009 featuring the wheat trial as well as some small acreage spelt/emmer trials. The Kelly’s have faced some challenges in organic food grade wheat production. One challenge has been weed management. Ragweed presents a special challenge because ragweed pollen makes wheat bitter and unsalable. Another challenge is the lack of local infrastructure for dehulling spelt. In addition, quality is important in food grade grains, and grain is tested for protein (needs to be above 13%), vomitoxin levels, and falling number. When it rains just before harvest, grain may start to germinate in the head. The germination causes an increase in enzymes that break down starch and proteins. Starch degradation has a greater effect on reducing the quality of flour. The longer the grain sprouts, the greater the amount of the starch-degrading enzyme formed. Falling number is a test that gives an indication of the amount of sprout damage that has occurred within a wheat sample. Generally, a falling number value of 350 seconds or longer indicates a low enzyme activity and very sound wheat quality. As the amount of enzyme activity increases, the falling number decreases. Values below 200 seconds indicate high levels of enzyme activity.
By Mary Barbercheck, Department of Entomology and PSU Extension Crop Management Team