At Last Some Good News!
All indications are showing that the El-Niño weather pattern is reducing and moving into a neutral state. What does that mean for us? First let’s get some information on El-Niño (and the opposite weather pattern, La-Niña):
El Niño is Spanish for ‘little boy’ while La-Niña means ‘little girl’. El-Niño describes ‘the warm phase of a naturally occurring sea surface temperature oscillation in the tropical Pacific Ocean’, southern oscillation refers to ‘a seesaw shift in surface air pressure which influences atmospheric circulation, and consequently rainfall and temperature in specific areas around the world. La-Niña refers to the cooling phase of the same temperature oscillation that causes El Niño.
As these sea temperatures rise, the air becomes more dry and humid, influencing hotter weather patterns. This is responsible for making our hot summers even hotter and severely limits the amount of rainfall across the country.
La-Niña has the opposite to effect with overall cooler temperatures and more rainfall. However, the rainfall can be more severe and cause flooding. La-Niña usually occurs after El-Niño and it may be on its way.
The El Niño-Southern Oscillation (ENSO) is currently in a Neutral state and the forecast indicates that it will most likely move towards weak La Niña state during spring and early summer. The likelihood of a La Niña phase during the coming summer months has drastically improved in the last few months.
The following maps indicate the rainfall and temperature (minimum and maximum) climatology for the early-spring (Oct-Nov-Dec) and the spring (Nov-Dec-Jan). The rainfall and temperature climate is representative of the average rainfall and temperature conditions over a long period of time for the relevant 3-month seasons presented here.
(Sourced from: https://southerntimesafrica.com/site/news/la-nina-weather-patterns-what-southern-africa-should-know; https://www.thesouthafrican.com/news/weather/el-nino-south-africa-summer-2018-2019/ and https://www.weathersa.co.za/images/data/longrange/gfcsa/scw.pdf)
Coping With More Water and Higher Temperatures
The reality is that higher temperatures and more water will bring their own challenges.
Coping with More Water
More water will mean more erosion and run-off. There are a few things to consider to ensure your farm can cope with the potential more water expected during 2020/ 2021.
- Make sure water infiltration is optimised to reduce unnecessary run-off. Applying COMPO EXPERT’s Kamasol® Aqua twice a month will reduce water pooling and ensure better water infiltration (https://www.compo-expert.com/products/kamasol-aqua ).
- Make sure drainage in orchards, paddocks and roads are sufficient.
- Also ensure channels and canals for excess water is clean and without obstructions.
- If water can be stored, make sure dams are lined, and dam walls are intact. Dams also build up silt that should cleaned to ensure more water holding capacity
- Ensure mulch has been applied and cove crops are grown where needed.
- Use a fertilizer with minimum leaching to ensure nutrients applied will not wash away. COMPO EXPERT’s range of high quality stabilised nitrogen (“slow release”) (https://www.compo-expert.com/product-groups/granular-stabilized-granular-fertilizers/novatec) and controlled release fertilizers (https://www.compo-expert.com/product-groups/controlled-release-fertilizers/basacote) (https://www.compo-expert.com/product-groups/partly-coated-fertilizers/duratec) will help in maintaining nutrients in the soil.
The effect of Kamasol® Aqua on the soil
- Increases water infiltration and its lateral distribution in the soil.
- Decreases water losses through runoff and percolation.
- It results in reducing irrigation between 15-30% in controlled irrigation strategies.
- It reduces drought frequencies between showers when applied before rain.
The effect of Novatec®, Basacote® and Duratec® on leaching and nutrient use efficiency
NovaTec® is an NPK compound fertilizer with nitrification inhibitor DMPP (3,4-dimethylpyrazolphosphate). It reduces N-leaching and increases N-efficiency. During the active phase of DMPP (4 to 10 weeks, depending on soil temperature and soil humidity) the transformation of ammonium to nitrate is delayed. As a result, N-availability is further adapted to the plants´ requirements, N-efficiency is increased and N-leaching is reduced. Ideal for broad acre crops.
- Continuous release of nutrients throughout whole growth season related to climatic conditions
- Nutrition in a single and easy application
- Best efficiency of nutrient use
- Reduction of application rate and frequency
- Minimized leaching losses with no contamination of groundwater
Duratec® from COMPO EXPERT adds two different nutrient release technologies; it supplies nutrients to the plant through: a) A quick release nutrients supply with stabilized Nitrogen through a nitrification inhibitor DMPP, ensuring an N supply over 6 – 10 weeks. And b) A controlled release of all nutrients over 3 months though Basacote® controlled release technology.
This ensures a high nutrient use efficiency and high quality crops with less additional fertilizer.
Coping with Higher Temperatures
Mineral nutrition of plants plays a critical role in increasing plant resistance to environmental stresses. The management of plant nutrients is very helpful to develop plant tolerance to temperature stress. Better plant nutrition can effectively alleviate the adverse effects of temperature stress by a number of mechanisms.
Temperature stress (high temperature) can cause premature leaf senescence, which leads to loss of chlorophyll, increased membrane damage and progressive decline in photosynthetic capacity. High temperature stress directly damages the photosynthetic apparatus and decreases both photosynthetic rate and duration of the assimilate supply.
Temperature stress (high or low) induces the production of reactive oxygen species (ROS) such as superoxide radical (O2–) and hydrogen peroxide (H2O2). The accumulation of ROS damages membrane lipids and can lead to the death of plant cells .Plants possess enzymatic and non-enzymatic antioxidants in order to scavenge ROS.
Nitrogen plays a very crucial role in temperature stress tolerance. At higher temperatures, the intensity of light is also very high. So high light intensity, as a function of high temperature, affects mineral nutrients uptake in plants and affect plant growth negatively. Of the mineral nutrients, nitrogen plays a major role in utilization of absorbed light energy and photosynthetic carbon metabolism. An excess of non-utilized light energy can be expected to occur in N-deficient leaves, where it leads to a high risk of photo-oxidative damage.
Among the mineral nutrients, Potassium (K) plays a crucial role in survival of crop plants under environmental stress conditions. K is essential for many physiological processes, such as photosynthesis, translocation of photosynthates into sink organs, maintenance of turgidity and activation of enzymes under stress conditions
Due to temperature stress the re-active oxygen species (ROS) are produced continuously as byproducts of different metabolic pathways. Magnesium improves carbohydrates translocation by increasing phloem export and reduces ROS generation and photo-oxidative damage to chloroplast under temperature stress (high or low) conditions. Maintenance of chloroplast structure by improving Mg nutrition enhances the photosynthetic rate under temperature stress, which in turn improves the productivity
Boron can increase the antioxidant activities of plants and thereby alleviate ROS damage induced by temperature stress. B application also improves the CHO metabolism and decreases the phenolic compounds in leaves. This in turn reduces the production of ROS species, enhances the photosynthetic rate and reduces the cell damage. This improves the yield by improving the temperature stress.
Manganese (Mn)Manganese (Mn) can reduce the adverse effects of temperature stress indirectly by enhancing the photosynthetic rate, and nitrogen metabolism in the plant body. Manganese (Mn) is also involved in the activation of many enzymes in plant systems and plays a crucial role in decreasing the production of oxygen free-radicals and increase the anti-oxidative compounds and enzymatic activities under temperature stress thereby may play a role in detoxification of ROS.
(2) (PDF) Alleviation of temperature stress by nutrient management in crop plants: A review. Available from: https://www.researchgate.net/publication/258518225_Alleviation_of_temperature_stress_by_nutrient_management_in_crop_plants_A_review.
Heat Stress Management via Plant Nutrition
Supplying plant nutrition in a balanced way has numerous benefits. One such a benefit is it will assist the plant in coping with heat (and cold) stress. The COMPO EXPERT product range include all nutrients to ensure a balanced nutrient programme for each crop.
Nutrimix® Complete and Nutribor® are foliar fertilizers with micronutrients, magnesium and nitrogen. These products can be used to ensure micronutrient levels are sufficient in plants and also to lessen heat stress already visible in plants.