Archive for November, 2015

7 Nov

Cover Crops Keep Carbon and Cash Where They Belong

Posted by Center for Sustainable Ag. in corn, cover crop, farming and climate change, organic, pasture, silage, soybeans, sustainable agriculture.

Originally posted on October 21, 2015 on the Farming & Climate Change Adaptation Blog

On-farm and field trials in Pennsylvania, New York and Vermont show that cover cropping produces a number of financial benefits for farmers and wider environmental benefits for the community. Cover cropping increases soil organic matter (a.k.a. carbon) and microbial diversity while suppressing weeds and stabilizing soils, which can help farmers transition to organic methods as well as improve their agricultural practices cost-effectively. Fields with a cover crop have less erosion and less runoff, meaning nutrients stay in the soils, better not only for soil quality and crop yields, but also for preserving water quality and ecosystem health.

While the benefits of cover crops researched by Northeast Extension teams in crop, field, and soils are clear, the prescribed planting methods, timing, and seeding rates need careful consideration for successful seed establishment and sufficient cover growth depending on a number of factors including the site conditions, harvesting schedules, and farmer circumstances.

In Westford, Vermont, a cover crop of radish, rye, turnip, and white clover was successfully seeded after corn was harvested at Tony Pouliot’s farm under the guidance of UVM Extension agronomy expert Heather Darby.

Pouliot was pleased to see his soil, the most valuable asset of his farm, protected – as you can see in this Across the Fence video.  Heather Darby and her team at UVM Northwest Soils and Crops provide invaluable advice to Vermont farmers in choosing appropriate cover crop seed mix, deciding on the methods and timing of planting whether before or after harvesting the cash crop, and many specifics related to the farm’s cropping systems, equipment available, location, topography and soil types.

A 2014 Cornell cover crop experiment with soybeans no-till planted into mulch from a winter cover crop at the Hudson Valley Farm Hub showed that a farm’s net profit was highest when seeding rates were double the recommended seeding rates of conventional soybean production. Five planting densities were compared and the crop population, weed suppression, and crop yields were measured.  Matthew Ryan’s report on cover cropping strategies and his research projects are part of Cornell Sustainable Cropping Systems Lab.

Soybean Yields Comparison

UVM Extension’s Northwest Crops and Soils program produces guidance and tips on interseeding cover crops for Vermont farmers growing feedstock such as corn and soybeans. Advice concerns the timing of seeding, the level and depth of seeding, available labor and proper equipment, and altering other management practice (e.g. pesticide applications and tillage), which would harm cover crops.  Importantly, research has found that cover cropping may have no negative impact on corn yields and can sometimes have a positive yield effect.

Additionally, when over-wintered cover crops are “terminated” with a roller crimper in the spring, the mulch mat which is formed suppresses weeds during the growing season for cash crops. In addition to increased profits to the farmer, the energy savings (resulting from less diesel fuel used, less fertilizers and a reduction in pesticide use) result in a reduction in greenhouse gas emissions from the farm.

A roller-crimper in the field

And taken all together, that’s how the benefits of cover cropping reach beyond the farmer to the community and the climate.

 

5 Nov

Dealing with Weather at High Ledge Farm

Posted by Center for Sustainable Ag. in adaptation, farming and climate change, flooding, food systems, organic, produce growing, sustainable agriculture.

Originally posted on September 30, 2015 on the Farming & Climate Change Adaptation Blog

The Betz family started High Ledge Farm in 1999. Paul and Kate Betz grow certified organic vegetables on a small parcel of 2.5 acres and manage a 4100 sq. ft. of greenhouses for plant and tomato production. They have a CSA program and sell their produce at the Montpelier Farmers Market.

The High Ledge Farm Booth at the Montpelier Market

Impact of Rain

The climate change effects that worry the Betz family are heavy rain events. These have resulted in soil fines (the smallest particles within the soil) rising to the surface and sealing it so that in seedlings have difficulty emerging. The Betz’ have experimented with the timing of their plantings and tried multiple plantings to increase the opportunities for seeds to germinate in these potentially adverse conditions.

This past year the farmers planted their carrots twice because of the risk of soils sealing and preventing sufficient germination. Planting twice meant two opportunities for seeds to germinate.

The problem is that any time bare soils are exposed directly to rain with minimal cover to protect them from the impact of raindrops, erosion can occur and soil structure can deteriorate with the possibility of fines rising with the excess water. By minimizing the time that bare soils are exposed directly to rain and keeping soil covered with a crop as much as possible will in turn reduce the possibility of fines and soil surface sealing.  The UVM Extension Center for Sustainable Agriculture has a fact sheet about controlling drainage and increasing the water holding capacity of soils. Rather than take a gamble with weather forecasts to anticpate the possilbity of soil crusting, improving soil composition with organic matter, and using winter cover crops to lessen impact of rain, will help soils retains more water.

Protecting soils from rain

Improving soil composition with organic matter and using winter cover crops to lessen the impact of rain will help soils retains more water. The Natural Resource Council provide a useful guide on the factors affecting soil crusting and measures which can be taken to improve soil quality

UVM Extension agronomist Dan Hudson explains that healthy soils not only hold water but can also help stabilize the movement of water and soil particles. Cover crops are a critical part of the soil system as they help support microbial activity which further enhances soil structure and organic matter in the soils. The key to healthy soils are:

  • organic matter in soils
  • debris and plant cover on soil surface
  • living roots in soils

Reducing risks with greenhouses

While the effects of climate change include heavy rains with impacts on soils and a longer growing season in Vermont, the temperature variations within the growing season are widening. This risk of a cold snap or heat wave can undermine any perceived benefit of a longer growing season.

Recognizing the variability and extremes of Vermont weather, farmers have turned to greenhouses and hoop houses in growing numbers.   Their strategies for coping with variable weather start from the ground up.  Maintaining and improving soil quality is essential with additions of organic matter, cover cropping, and minimizing tillage. Soils which have more plant matter including living roots in the soil and leaves on the soil have increased microbes which help retain more moisture during dry spells and can cope with absorbing more rainfall during wet periods.

While soils with higher organic matter content can help mitigate wider ranges in precipitation, greenhouses help mitigate wider ranges in temperature. Using a greenhouse to control the environment, the Betz family benefits at both the start and the end of the growing season so that the swings in temperatures during Vermont’s shoulder seasons of spring and fall don’t result in swings in income.

Contributions from Catherine Lowther, Goddard College, Faculty in the BA in Sustainability Program, Chair of the Sustainability Committee and UVM Extension Center for Sustainable Agriculture

Skip to toolbar