- Author: Molly Nakahara
- Author: James Muck
As we farmers and ranchers determinedly pace the rows of trees, as we tread upon the fields of foliage and flowers, and herd our stock across green and brown pastures, an underworld of microbiology and geology hums beneath our feet. Hold a handful of soil in your hands and you hold billions of micro-organisms. More importantly, you hold the cornerstone of productivity on your farm. With all of the work required by the production of food and fodder, it is easy to overlook the significance of soil. It is also easy to postpone the improvements to the soil that can greatly impact the yields and health of farm plants and animals. It is vital for all farmers, ranchers, and orchardists to incorporate soil building into our annual routines.
The first and most important step in improving your farm and ranch soil is to understand the make-up of your soil and create an action plan for improvement. To do this, you will need to take a soil sample for analysis. To accurately take a soil sample for analysis by a professional laboratory, a very specific protocol must be followed. Please watch our recently published video on soil sampling for more information (https://youtu.be/eo2pS9mSZi8) We also have a publication on taking a soil sample for analysis available on our Foothill Farming website (http://ucanr.edu/sites/placernevadasmallfarms/files/142586.pdf).
Once you have your results from your soil test, you will need to spend some time interpreting the information. This is often a sticking point for farmers- all of that chemistry and so little time to understand what to do. Soil is a complicated living system and making a mistake in what and how much you add to your soil can have dire consequences for your crops. That sounds scary, so no wonder farmers are intimidated.
The good news is that you can ask the soil lab that analyzed your samples to give you recommendations for soil amendments and application rates. If your farm is organic be sure to tell the lab that you want organic advice, otherwise you will get conventional farming suggestions. The soil lab, at a minimum, should be able to tell you how much nitrogen, phosphorous, and potassium, you will need to apply in order to achieve good yields. Depending on the lab and the tests you requested you can also get recommendations for how much and what kind of lime to apply; if you need trace minerals like boron, sulfur, or zinc; and how many tons of compost you should add. Different soil labs use different test methods so it is a good idea to use the same lab to test your soil each year. In other words, once you get going on a soil fertility plan from one lab, stick with it. Soil building takes years so you must be patient and consistent in both your testing and following of the lab's recommendations.
You do not have to get recommendations from a soil lab. You can learn how to read your soil test results and then develop your own soil building plan. To learn how to read soil lab test results start by taking one of the interpreting soil test results workshops offered by the UC Cooperative Extension. Be sure to keep an eye on the event calendar on the Foothill Farming website for the next workshop.
- Author: Molly Nakahara
A quick scan of drought related news is not good for my anxiety levels. A March 21st article in The Atlantic reports how our warmest winter in 100 years (by 4.4 degrees on average) is impacting agriculture across California: 17,000 farmers lost their jobs in 2014 and cost the ag sector $2.2 billion. For the first time in 75 years, the Department of Water Resources Sierra snowpack survey for April 1st had no snow to survey. The 2012-2014 California drought is reported to be the worst in 1,200 years! I am growing tired of watching the weather forecast as well. The pattern thus far: a storm is forecast, the storm arrives and delivers a fraction of what was expected. My new plan is to stop focusing on the lack of rain and snow and start getting serious about building drought resilience into our farm plan.
The reality is that we won't be able to sink a new well or dig a new pond. We are a small farm with very limited capital purchasing power. Does our lack of financial wiggle room mean that this drought may put us out of business? I am hopeful that we can continue to farm within the new parameters that this drought may impose on our business. But we won't be able to do this without a plan.
What is the worst case scenario on your farm or ranch? On my own farm, the worst case scenario would be the complete suspension of our irrigation water allotment. If our water allotment was drastically decreased, could we still make a profit from our farm? Here's a look at what we are planning to do to increase the drought resilience of our land and business.
A simple first step is to increase our soil organic matter. We traditionally grow both summer and winter cover crop on fallow ground. This summer's growing season, we are taking even more land out of row crop production and will plant more summer cover crops. Our favorite is sorghum Sudan grass. Unlike Johnson grass which it is very similar to in appearance, Sudan grass does not grow rhizomes and spread underground. It requires very little water and is a great way to protect open ground in the summer. According to UCCE Horticulture and Small Farms Advisor, Cindy Fake, a 1% increase in soil organic matter results in an additional 16,000 gallons of water retained per acre foot of soil! That is a lot of water. This ATTRA publication has a lot of information on creating drought resilient soils: http://cses.uark.edu/ATTRA_drought.pdf
Another goal this season is to understand exactly how much forage our pigs are able to access from the irrigated pastures we raise them on. I want to know exactly what it would cost if we had to buy in all of the feed for our animals. Understanding the financial impact that the loss of our irrigation water would have on our farm will help us make decisions about the size of our hog herd. If we decrease by 25%, can we keep our feed bill affordable? If there was no water at all, how much would it cost to keep our breeding animals alive?
We irrigate our row crops as efficiently as we can. We deliver water through drip tape and irrigate in the evenings once the day has cooled and evapotranspiration loss is decreased. But I am finding that this is still not enough to make our farm truly drought resilient. I need to know at what point in the growth cycle the crops I produce are most susceptible to water stress. In other words, how can I achieve profitable yields with the least amount of water possible? If I had to use my residential water supply to grow a crop, what is the least amount of water I could utilize without seriously impacting yield? Here is a link to a publication on water efficiency and the critical periods for water stress in orchard crops and vegetables: http://ucanr.edu/sites/placernevadasmallfarms/files/180093.pdf.
Understanding the economics of each of my crops is vital to drought resilience. I need to know which crops to prioritize in the face of limited irrigation water. Are dahlias or sunflowers a more profitable crop for us? Can we increase our early season production and limit production when the temperatures hit the high 90s? I cannot make these decisions without a thorough understanding of the income and expense associated with each crop. The crop metric calculators created by UC Extension can assist you in determining the profitability of each crop you grow. http://ucanr.edu/sites/placernevadasmallfarms/UCCE_Enterprise_Calculators/. By combining my understanding of which crops need water and when with my knowledge of income and expense for each crop, I can begin to create my drought contingency crop plan.
Out of habit, I just checked the weather forecast and saw that some rain is predicted for the end of the week. The predicted moisture will help the cover crop and pasture grow, but it won't alter the long term effects of this drought.
News links and References:
Scott, H.D., L.S. Wood, and W.M. Miley. 1986. Long-term effects of tillage on the retention and transport of soil water. Arkansas Water Resources Research Center. Publication Number 125. 39 p.