Dairy Cropping System Project – Forage Quality and Quantity, Part I
An interdisciplinary team of Penn State and USDA-ARS researchers evaluated a Sustainable Dairy Cropping System to test the hypothesis that a dairy farm can minimize off-farm inputs and environmental impacts, and be productive, profitable, and sustainable.
Established in 2010 at the Penn State Agronomy Research Farm, the farm produced forages and grains at 1/20th the scale of an average sized Pennsylvania dairy of 240 acres. The farm included two diverse six-year crop rotations with perennial legumes, cover and green manure crops, and winter canola. Within each crop rotation two management practices for no-till crop production were compared: 1. Forage Rotation compared injected manure (IM) to broadcast manure (BM); 2. Grain Rotation compared a combination of weed management strategies designed to reduce herbicide (RH) use relative to a "standard" herbicide (SH) weed management program.
The two diverse cropping systems were designed to provide all the forage and feed for 65 lactating cows housed in a tie-stall barn, 10 dry cows and 75 young-stock. Crops were analyzed for quality, yields were measured for quantity, and milk production of the "virtual dairy herd" was simulated using the 2001 NRC and the Penn State Dairy Herd's performance, since they received feeds similar in quality to those produced at the research farm. Performance of the two farm scenarios (BMSH or IMRH) were compared from 2010 through 2017. A financial analysis was completed using FINPACK®. Those results will be covered in Part II.
The cropping year for the Virtual Dairy Operation began in 2010 with the assumption that a crop farmer was transitioning into dairying. The operation had the storage structures for ensiled feeds and basic facilities to house animals. Ensiled feed was stored in five upright silos, Ag bags, or as wet wrapped round bales. The hay-crop season started in May 2010 and youngstock were fed during the summer. The lactating herd was purchased in October 2010 after corn silage was harvested
Crop yield and quality were used to simulate milk production for a virtual dairy herd and whole farm performance comparing the two-dairy cropping systems. Mimicking a real farm, forages and grains were ensiled at time of harvest. If tonnage from a particular harvest exceeded the capacity of the silos, Ag bags were used. Also, later cuttings of hay-crop forage were wet wrapped as round bales. Most wet wrapped round bales generated crop sales, however, in drought years they were needed to feed the herd. Depending on the year, some dry hay was used for crop sales.
Forage and Feed
Corn silage yields and quality matched very closely to local farms in the Centre region and near the research plots. Weather conditions, especially drought, took its toll on yields in 2012 and 2016 (Table 1). A goal was to have carry over of corn silage from one harvest to another to avoid the reduced milk production that occurs when feeding corn silage that has not gone through a complete fermentation. Over the course of the project, acreage was increased to produce more corn silage as that was more advantageous to milk production compared to the amount of corn grain harvested and utilized.
Table 1. Corn silage quality and quantity comparison between BMSH and IMRH.
A large component of the project was the production of hay-crop forage. First cuttings were ensiled with aftermath cuttings used for dry hay or wet wrapped round bales. In the BMSH system, pure alfalfa and an alfalfa/grass mix were produced compared to the IMRH that produced only the alfalfa/grass mix. The drought year of 2012 required utilizing multiple cuttings of haylage to meet the forage needs of the herd. The other years, the quantity of the first cutting was usually adequate to meet the inventory needs from harvest to harvest. However, there were some years when the wet wrapped round bales were needed for the herd, especially in the IMRH scenario.
Sorghum-sudan was planted and harvested as silage to meet the forage needs of the herd in 2012 because of the drought. This forage was excellent for the dry cow and heifer rations. It was later incorporated as part of the normal crop rotation. Most times this silage was stored in Ag bags.
A challenge with the alfalfa/grass mixed silage in both scenarios was the high protein content, which made it difficult to keep protein in line for the dry cows and heifers. Ryelage was initially incorporated into the cropping rotation to provide a high fiber and low protein forage (Table 2). However, towards the end of the project, with improved fertilization, both quality and quantity increased substantially by 2017. Ryelage was then incorporated into the lactating cows' diets.
Table 2. Ryelage quality and quantity comparison between BMSH and IMRH.
In the virtual dairy scenario, the corn grain and soybeans were grain banked with a local feed mill since long-term storage on the farm was not available. Corn grain was included in all grain mixes for the animal groups. The soybeans were utilized solely for the lactating herd. Depending on the yields, soybeans did not always meet the needs of the herd for 12 months. When beans ran out, purchased beans were calculated into the feed cost at market value.
In two out of eight years, the soybeans yielded much higher in the SH system compared to RH. Yield differences in 2011 and 2012 were attributed to population differences due to slugs and cold, wet soil. Corn yields only differed between treatments once, however, the total amount produced was more than adequate to feed the dairy herd and keep feed costs reduced.
Cropping Enterprise
The efficiency of the cropping system is a critical component to the success of a dairy operation. This has a direct impact on the total feed costs per cow. The cost of home raised feeds includes the direct costs coming from seed, chemical, fertilizer, and custom hire (wet wrapped round bales or Ag bagging) in addition to partitioning overheads for the cropping system, plus depreciation and the value of owner's labor and management. Table 3 compares the net farm income, crop sales, change in inventory, and the unit costs for the various feeds. The unit cost for the alfalfa and alfalfa/grass mixtures are not reported because they were broken out based on if they were stored as silage, hay, and wet wrapped round bales. This is not the typical approach to calculating the unit cost for hay-crop forage. For this project, it was important to differentiate the costs since a lot of the hay-crop forage was for crop sales (wet round bales). It was helpful to realize the cost of that storage method when determining a market price.
The goal is to produce forages and grain cheaper than what the current market price is offering. The virtual farm did an excellent job producing corn grain and soybeans that were cheaper than market price. All the soybeans were used for the milk cows and all the corn grain supplied the needs for the herd. Any excess corn was sold. At the beginning of the project, corn silage yields were not stellar, and the market price was better than the home-raised cost. By 2012, the virtual farm had made improvements in cropping management that resulted in a more sustainable price. It is not unexpected for small grain silage and sorghum-sudan silage to be close to market price. As the farm improved in fertility and higher yields were obtained, the unit costs for these two forages showed a lot of improvement by 2017.
There was a slight advantage to crop sales for the BMSH scenario. Having stands of both alfalfa and alfalfa/grass mixture provided a slight boost to the BMSH scenario (over $6,000 on average for the 8 years compared to IMRH). During the drought years, the IMRH was hit hard on the alfalfa/grass inventory with most being used to feed the herd. Having the alfalfa available in addition to the alfalfa/grass mixture in the BMSH scenario provided ample feed for the dairy in addition to surplus crop sales. In addition to the change in purchased feed that needs to occur to offset a shortfall from a drought year, the farm also faces a more hidden adjustment in the crop inventory change value. Feed in storage may be significantly reduced by drought year yields. This translates into a negative inventory change that directly reduces farm profit.
Another aspect to the project was the production of other crops that are included in the crop sales in addition to the hay-crop forage. The virtual farm raised canola, which was sold to a business that generated oil that could be used to fuel equipment. The company also produced canola meal. In the first few years' straw was produced, and the cereal grain, rye, or wheat was sold. Also, corn grain was produced at a level that exceeded the farm's needs and was sold when corn grain prices were high. During the last few years of the project, excess corn silage was sold. This became very beneficial to the operation during drought years when hay-crop forage yields were compromised, the virtual farm had other crops that could be sold.
Both scenarios, BMSH and IMRH, provided excess crop production that could be used for crop sales. All forages and grains were home-raised at competitive values. Excess crops for sale are a risk management strategy that helps protect the farm against fluctuating commodity prices and provides some drought resilience during short crop years. Part II will examine how quality and yields affected animal performance and profitability.
Table 3. Cropping enterprise comparison between the BMSH and IMRH scenarios.
References
Binder, J., H.D. Karsten, D. B. Beegle, and C. J. Dell. 2020. Manure injection and rye double cropping increase nutrient recovery and forage production. Agronomy Journal. Doi:10.1002/agj2.20181
Karsten, H. D., Adams, T., Dell, C., Ishler, V., Tooker, J., Wallace, J., Beck, T., Beegle, D. B., Curran, W. S., Hoover, R., Jahanzad, E., Kleinman, P., Richard, T., Sutradhar, A., Malcolm, G. M., & White, C. (2020). Advanced sustainable cropping systems for dairy farms in Northeast. SARE Outreach: College Park, MD.
Summers, H., H.D. Karsten, W. S. Curran, and G.M. Malcolm. 2021. Integrated Weed Management with Reduced Herbicides in a No-till Dairy Rotation. Agronomy Journal. DOI: 10.1002/agj2.20757
