Soil testing throughout the project helps determine if any soil amendments are needed. Photo: Kristi Kraft
The Models for the Future project also features study circles for young, establishing, women, and Latino growers to meet and discuss the many challenges and opportunities that come with beginning a farm. Model plots include vegetable and berry crops rotated with cover crops, and apple orchard pre-plant plots. The apple plots demonstrate how various cover crops can be used following orchard removal to potentially improve soil health and reduce nematode pressure for the next tree planting.
As opposed to strawberry and vegetable production, apple trees appear to be nearly permanent fixtures on the landscape. While an orchard can be in the ground for decades, the productivity and profitability of modern orchards begins to decrease after fifteen to twenty years. To keep acreage profitable, and to keep up with the changing tastes of consumers, growers replace older blocks of trees regularly to ensure a high quality apple crop of the most exciting new varieties. Rather than removing one orchard block and planting another immediately, it is highly advisable to take the land out of fruit production for at least two or three years to reduce any apple-specific pest, disease, and/or nematode pressure that may have built up in the soil during the years the site had been in continuous apple production.
Modern apple plantings can remain productive for fifteen to twenty years. Photo: Tianna DuPont
In four apple demonstration plots established across Pennsylvania in 2015, initial soil samples were taken to determine if any nutrient amendments were needed, analyze soil health, and to determine if nematodes were a problem. Cover cropping began in Spring of 2015, with sorghum-sudangrass. The sorghum-sudangrass selection used in the plots contains high levels of cyanogenic compounds that reduce the growth of plant-parasitic fungi and nematodes. To get the full effects of these beneficial compounds, the grass was flail mowed and incorporated into the soil within thirty minutes after mowing with a disk or plow, followed by a cultipacker. Incorporation and cultipacking keeps the beneficial compounds in the soil, as they would otherwise volatilize into the atmosphere.
The sorghum-sudangrass was followed by rapeseed in the fall of 2015, and the plot was reseeded into rapeseed this summer. Rapeseed also acts as a biofumigant, which may further reduce the population of plant-parasitic nematodes in the plots. After the rapeseed is mowed and incorporated a final time, the soil will be analyzed again to make additional soil adjustments, and an endophyte-enhanced grass mix will be seeded to establish a ground cover for the winter. This ground cover will become the between-row cover for the new orchard. In the spring, the grass in the tree rows will be killed, and the new trees will be planted directly into the killed sod in a high density trellis system. This system will allow the growers to pick a small crop of fruit in the year following orchard establishment, and should develop a full crop in the subsequent years. This is a great improvement to moderate density systems that can take five to seven years to produce a full crop!
Flail mowing and incorporating the rapeseed helps to release its biofumigant compounds. Photo: Kathy Salisbury
Using these cover crops, the Penn State Start Farming team and grower cooperators across the state hope to showcase how these best management practices can lead to the establishment of a healthy and productive new orchard planting that will thrive for another fifteen to twenty years. In addition to serving as model plots, these sites will serve as a venue for upcoming winter study circle sessions, and provide the extension team the opportunity to create educational content for growers based on real world, working farms.
Interactive budgets from "Models for the Future" fruit and vegetable plots allow growers to assess the costs and benefits of cover crops and other sustainable practices in their own operations. This project is supported by the Agriculture and Food Research Initiative of the National Institute of Food and Agriculture, Grant # 2015-70017-22852.