Project Overview
Commodities
- Vegetables: greens (leafy), greens (lettuces)
Practices
- Crop Production: conservation tillage, cropping systems, fertilizers, no-till
- Education and Training: on-farm/ranch research
- Pest Management: cultivation, mulches - general, mulches - living
- Production Systems: organic agriculture
- Soil Management: composting, earthworms, green manures, organic matter, soil analysis, soil chemistry, soil microbiology, soil quality/health
Summary:
Before we were even accepted for the Farmer and Rancher Grant, we have witness first hand, from a visual standpoint, how much over tilling can affect soil structure. The soil is more prone to erosion, drying out, and has always seemed to yield less than when planting into ground that has just come out of a succession of cover crop. This grant gave us the opportunity to take a closer look on what is actually happening every time you till soil and if that will have an adverse affect on both soil structure and the biome that is crucial in the relationship between your roots and the nutrients it needs. It also let us see if compost left on the soil surface could be used as a mulch and weed suppressor, which would hopefully improve yields and time spent in the field weeding and tilling. Overall we were left with mixed results.
We began the process with building a self loading compost bin/spreader (video - https://www.youtube.com/watch?v=vcU8c44xQhI). In the beginning we envisioned the spreader having the capability to spread the compost automatically using an auger system. It is important in our permanent bed system to apply the compost directly on our raised beds and not in the walkways. After some further investigating we found that the compost we purchase is usually too heavy/wet and it would end up bridging, which would become a nuisance. We would like add that if the compost used was finer or dryer it might be possible to use a manure spreader or auger system compost spreader. In the end, the compost spreader we designed and built worked great! It became a two man operation but it was very efficient and enabled us to spread the compost directly over our raised beds, right where we need it. Two loads with the spreader was enough to cover one of our hundred foot beds but it could be made larger depending on your tractors power and size. It can even be used in the high tunnels which is a huge plus considering that in the past we carried the compost in by the bucket load. As we have always done in the beginning stages of trying something new, we hope that another farmer out there will stumble across our video on YouTube and have an idea of where to start.
The next part of the process was planting into the trial and control beds which were in large plots on an every other bed basis. The control beds had compost applied and that compost was tilled into a six inch depth. The trial or test beds had compost applied but the compost was left on top of the soil in hopes to create a weed suppressor or mulch. We found that not tilling the trial beds saved our farm about seven minutes per bed. During the average season we plant roughly eighty five hundred foot beds which would end up being about ten hours worth of tilling just for lettuce, which is quite substantial. Each week we planted successions of lettuce into the control and test beds at the same time and each bed in those successions were watered and weeded at the same time as well. After some time, we realized that after hard rains, the compost left on top of the trial beds would become rock hard, which made it difficult to transplant the lettuce into. The hard compost also seemed to make it difficult to weed with our hand held hoeing tools. Eventually, we were forced to use a tilther, which is a small drill powered tool that breaks up the top inch of soil. The soil beneath the compost was untouched as to not affect the trials. The time spent tilthing did offset the time spent not tilling the trial beds, so in the end, we did not save any time. If an auger type compost spreader was used it is possible that it would have broken up these larger pieces of compost while spreading it at a more consistent rate and may have made it possible to avoid tilthing. Another downfall of leaving the compost on the soil surface was that, after a hard rain, the compost seemed to have an increased chance of eroding into the walk ways between each bed compared to the beds with tilled-in compost. Throughout the process we shared our experiences on our social media pages so that other farmers or people interested could learn from our findings.
Overall, the trial beds did show some promising signs when it came to using the compost as a weed suppressant. On a scale from one to five, one being the least amount of weed pressure and five having the highest amount of weed pressure, the test beds had a somewhat lower rating with 1.75, while the control beds, beds where the compost was tilled in, had a rating of 2.38. On average, each bed was manually weeded once throughout the lettuce lifespan, so therefore, time spent weeding was not affected as far as times weeded, though the control beds with a higher weed pressure rating most definitely took longer to weed in general. Looking back, the actual time spent weeding each individual bed would have been a better way to document and would have given us a better picture of how much time using compost as a mulch was actually saving us. We also attempted to measure disease pressure for each bed. This was inconclusive as plot one used in our trials was hit with hail in later July of 2024. The successions before hand in plot one had all battled with disease at an equal rate. This was mainly due to the heavy rains and storms our area was hit with during most of the growing season. In plot two, neither the test or control beds showed higher signs of disease resistance.
The most crucial part of our documentation was to see if using compost as a weed suppressant and mulch would lead to higher yields. Keeping in mind that seven of the thirty four total beds monitored were affected by a large hail storm, the test beds did indeed show quite a rise in overall yields. Throughout the two plots, the control beds planted with salad mix yielded an average of 44.5 lbs harvested per one hundred foot bed while the test beds planted with salad mix showed an average of 49.5 lbs harvested per one hundred foot bed. Additionally, control plots planted with head lettuce yielded an average of 64 heads harvested per one hundred foot bed while the test beds planted with head lettuce yielded an average of 87 heads per one hundred foot bed. Though it may be a small margin, any system that may increase crop yields in a small organic vegetable farm needs to be considered. More monitoring would be needed to determine if this type of system would lead to overall higher yields throughout different seasons and in crops other than lettuce.
Project objectives:
- Evaluate the efficacy of using compost, as both a mulch and weed suppressor.
- Evaluate if such practices will promote higher yields and profits, while cutting down on work load, such as weeding and tilling.
- Share our findings with the community, and other farmers, through an on-farm showcase, social media, and our local newspaper, as well as posting a DIY construction video of our Self-Loading Compost Spreader design.