Posts Tagged: soil
Soils perform vital functions, and are the basis of the ecosystem. Healthy and productive soil is vital for our survival. It is an amazing resource and fascinating to learn about.
- Soil facts – definitions, career information, soil basics, glossary, and regulations for moving soils
- Painting with soil – Jan Lang’s images of the Lewis and Clark Expedition
- 10 key messages to understanding soils
- Find out about your state’s soil
- Links for students and teachers – available for grades K-6, 7-12, and college level
- Videos and webinars
- Dig It! The Secrets of Soil
- NRCS photo gallery – natural resource and conservation related photos from across the United States
- And more
The spring edition of California Agriculture has a varied collection of articles. You can read about solutions for nitrate in drinking water, protecting California forests form catastrophic fire, agricultural advances, and the history and legacy of the Morrill Act.
- No-tillage and high-residue practices reduce soil water evaporation
- Research and adoption of biotechnology strategies could improve California fruit and nut crops
- Regulatory status of transgrafted plants is unclear
- New quality index based on dry matter and acidity proposed for Hayward kiwifruit
- Honoring 150 years of accessible higher education
- For 150 years, UC science and agriculture transform California
- UC’s land-grant mission fuels nation’s growth, prosperity
- Report seeks solutions for nitrate in drinking water
- UC leads effort to protect California forests from catastrophic fire
- Conservation tillage achieves record acreage, yields
We have many highly salt sensitive crops in Ventura County: strawberry, avocados, blueberries. Rainwater, the purest kind, is excellent for leaching salts, but, in years with low rainfall, salt accumulation and resulting toxicity is a big concern.
Plant reaction to salts varies among varieties, stages of growths and environmental conditions and, perhaps most importantly, with the type of salts that they are exposed to. We typically determine salinity of water and soil by measuring Electrical Conductivity (EC): the more salts are present the greater is the capacity to conduct electric current. In fact, there are guidelines for most crops that show at which EC level you would expect negative effects on plant growth and productivity. Yet there seems to be a discrepancy between the guidelines and what actually happens in the field. For example, University of California (UC) guidelines suggest that strawberry injury and yield reductions can occur at EC=1 dS/m. However, in several Ventura County fields we have healthy productive strawberry in soils with EC >4 dS/m. These large differences in tolerable EC levels result from the fact that the guidelines were developed using sodium chloride, while Ventura county soils/waters most frequently have calcium and sulfates as primary components of EC. Recent studies at UC Riverside showed the specific negative chloride effect on strawberry fruit production, while studies elsewhere have documented that sodium can also be more harmful than other ions such as calcium and potassium. Because we have calcium-rich soil, and even irrigation water often contains calcium sulfate, our crops can manage well even with EC levels well above 1 dS/m. In fact calcium and magnesium help to counteract the negative effects of sodium in the soil salt solution.
In a demonstration, we wanted to show that a very salty water (EC=20 dS/m) will have different effects on mature strawberry plants depending on the ion composition of the salts in that water. Indeed, after four days of watering with sodium chloride solution, the plants had severe injury symptoms and were dying. However, the same salt concentration of potassium sulfate only resulted in slight marginal leaf burn and mild stunting. Plants irrigated with distilled water (that imitated rain water) looked perfect, of course.
The important points of these demonstrations and field evaluations were:
- EC values in water or soil analyses only show total salinity and one needs to look at specific ions in the report to evaluate the potential effects on sensitive plants.
- Sodium and chloride are a lot more damaging that potassium and sulfate and we’re planning to evaluate several other salts and develop realistic thresholds for safe strawberry production in their presence.
- At high concentrations in the root zone fertilizers (such as potassium sulfate, a ‘safer’ salt) can injure plants and reduce their productivity
- Typical irrigation with drip lines placed between planting rows does not affect salts in the root system, unless excessive amount of water are applied to induce leaching.
The Natural Resources Conservation Service (NRCS) provides many resources for public use. In addition to educational resources, the NRCS has some financial assistance programs available to help eligible landowners and agricultural producers plan and implement conservation practices.
These programs address natural resource concerns and include: saving energy; improving soil, water, plant, air, animal and related resources.
Specific programs include:
- Agricultural management assistance
- Agricultural water enhancement program
- Air quality initiative
- Cooperative conservation partnership initiative
- Conservation innovation grants
- Conservation stewardship program
- Environmental quality incentives program
- Emergency watershed protection program
- Wildlife habitat incentive program
UC Farm Advisor Oleg Daugovish will hold an Irrigation field day Thursday, April 19 from 9:00 am to 11:15 am.
Scheduled topics include:
- Update on conditional waiver and requirements for irrigated lands in Ventura County
- Evaluation of three differing irrigation regimes in California strawberry
- Salts and soil analyses in strawberry beds under different irrigation regimes
- Soil test results interpretation and corrective management
- View experiment plots onsite
VCALIG educational credits have been requested from the Los Angeles Regional Water Quality Control Board.
There is no cost to attend. If you have questions, require translation into Spanish, or to register please contact Oleg Daugovish at 805.645.1454 or firstname.lastname@example.org. More information can be found on the agenda.
In the event of rain, the meeting will be held at the UCCE Conference Room located at 669 County Square Drive in Ventura.