Soil Health
Overview
- Healthy soils can provide increased water-holding capacity, increased nutrient availability, and greater microbial activity, which can help reduce disease pressure and improve root growth.
- Soil pH, soil fertility, and organic matter are considered as the important aspects of soil health.
Soil pH
- Soil pH should be tested at least annually and maintained between 5.8 - 6.5.
- It can take 6 to 24 months to adjust the soil pH to optimum depending on the soil buffer capacity, moisture, temperature, and aeration.
- Irrigation water in Florida is high in bicarbonates and increases soil pH over time.
- Irrigation water acidification, elemental sulfur application, or use of acidifying fertilizers are recommended to reduce soil pH.
- Soil pH reduction with acid injection into irrigation is faster compared to elemental sulfur soil application, but the effect of acid injection is short term versus elemental sulfur.
- Long-term use of ammoniacal fertilizers will also result in lowering the pH by nitrification.
- Low soil pH exacerbates nutrient leaching problems especially for calcium, magnesium, and potassium.
- High soil pH makes micronutrients unavailable while pH below 5 makes most micronutrients reach toxic levels for plants.
Organic matter
- Provides resources for soil microorganisms.
- Soil microorganisms assist in making nutrients available to the trees.
- Can increase water and nutrient holding capacity.
- Can reduce erosion and limit weed growth.
- Composting and cover crops add organic matter to the soil.
- Composting can be done by broad cast application within the rows.
Cover crop management
- Current vegetation should be mowed before planting cover crops.
- Herbicide may be applied to reduce germination competition.
- Annual cover crops should be planted at the beginning of the rainy season (June/July) and then again at the end of the rainy season (October/November).
- Mixing legumes with non-legumes in a cover crop mix can help increase microorganisms associated with nitrogen cycling.
- Planting can be done with a no-till seed drill to reduce impact to the citrus roots in the row middle, or by broadcasting the seeds.
- Standard mowing practices will keep the biomass within the row middles.
- To build a seed bank, mowing and termination of the cover crops can wait until after they have flowered and formed seeds.
Resources
- Citrus Soil pH Management
- Soil and Leaf Tissue Testing for Commercial Citrus Production
- Citrus Soil pH Testing Procedures
- Diagnostic Nutrient Testing for Commercial Citrus in Florida
- Flatwoods Citrus Best Management Practice: Soil Stabilization
- How to Characterize Soil Variability in Florida Citrus Groves as It Relates to Tree Growth and Yield
- Soil Sampling Procedures
- Soil pH Management for Optimum Commercial Fruit Production in Florida