Integrating Grazing in No-Till Systems on a Grain Farm

 

 

The adoption of no-tillage systems in Pennsylvania creates opportunities to graze after harvest. This case study examines the integration of grazing and no-tillage on a grain farm.

 

Grazing is a cost-effective method to feed beef cattle. The cost of grazed forage is typically half that of fed forage (Figure 1). However, if crop residue can be grazed, the cost to feed beef cattle can be reduced even more, and grazing offers the opportunity to get more value out of cover crops. The widespread adoption of no-tillage systems in Pennsylvania opens up exciting new opportunities to graze crop residue and cover crops after grain harvest to meet the forage needs of beef producers.

 

 

No-tillage has many benefits for soil management (see list below). Soil erosion is effectively controlled due to high and permanent soil protection and stable soil aggregates. The use of no-tillage leads to high surface soil organic matter that is resistant to compaction. The stable soil structure beneath that layer with a firm matrix holds up grazing animals much better than tilled soil. The soil matrix is interspersed with many large and small pores created by soil organisms and decaying root systems, guaranteeing good aeration and water percolation. Using no-tillage therefore reduces the threat of soil compaction.

 

There are other reasons why integration with grazing can help improve soil health in no-till systems. The animals help tramp organic matter onto the soil surface and deposit urine and manure on the soil to improve soil fertility. Grazing also helps add value to cover crops, making their costs and management easier to justify. On the other hand, grazing also has to be managed carefully or the cover crop and crop residue may be overgrazed, resulting in soil erosion, and soil can be compacted, resulting in reduced aeration, greater runoff, and reduced performance of crops planted after a field has been grazed. Grazing also involves an initial investment in fencing and watering infrastructure, and continued investment in management of the animals. In addition, one also has to think about feeding the animals when the grain crops are in the field.

 

Cropland used for grain production typically lies fallow for six or seven months of the year (Figure 2). Planting cover crops after or in main crops is recommended to maintain a “living root” in the soil year-round (Figure 3). Cover crops help improve soil structure with their root systems. Beneficial soil organisms that live in the crop rhizosphere are sustained. Cover crops help reduce runoff and soil erosion. Cover crops take up nutrients, protecting them from leaching. Cover crops can also liberate nutrients, making them more available to following main crops. Leguminous cover crops fix atmospheric nitrogen, which can benefit following crops.

 

 

 

However, it usually takes years before soil improvement benefits of cover crops can be noticed, while the cost for seed and management are immediate. If the farmers can get immediate return from cover crops while maintaining most of the benefits, it becomes a lot easier for farmers to justify using them. Hence the importance of grazing (or harvesting for forage) of cover crops to stimulate adoption.

 

We studied the integration of grazing and no-tillage on the Double B grain farm in McAlisterville, Pennsylvania, from 2014 to 2017. Four generations of the Brubaker family live on this farm, which produces corn, soybeans, oats, and spelt (Figure 4), as well as broilers and Limousin cattle. They farm 400 acres, 220 acres of which are rented ground.

 

 

The Brubakers started using no-till planting in the 1990s. The farm has been in continuous no-till since 1996. Crops are grown on the contour in strips laid out in their conservation plan designed by USDA-NRCS. Until recently, cover crops were only grown after small grain harvest. However, after becoming aware of the importance of cover crops for soil improvement, they started using them after all their grain crops in 2012. The cover crops include radish/ryegrass/crimson clover mixes after early harvested crops, and rye for later planting.

 

The Brubakers graze approximately 50 bred cows plus calves, for a total of 90 animals, primarily of the Limousin breed. They sell embryos as well as beef. The mainstay of their grazing needs is met by cool-season perennial pastures. A challenge they face is to meet grazing needs in the winter and summer. Since soils on their farm tend to be droughty, summer forage supply is a special concern on this farm.

 

We focus here on the fields around the homestead, which include 43 acres of perennial pastures and 39 acres of grain crops (Figure 5). The perennial pastures are divided up into about 22 paddocks with permanent fencing so cattle can be rotated frequently, usually on a daily basis. After grazing, the pastures are rested for at least a month before they are grazed again. Most perennial pastures are cool-season grass/legume mixes. Growth of cool-season pastures slows down severely on this farm with droughty soil types, which creates a challenge for grazing in the summer. Therefore, the Brubakers planted two strips of switchgrass in Field 2 to meet grazing needs during the summer. Research has shown that warm-season perennial grasses show good potential to meet summer grazing needs for beef farmers. However, establishment of warm-season perennials on this farm has been slow, and after several years their productivity is still marginal.