#33 - Nov 2019 - Garden Stuff - © Sandy Lang - slang@xtra.co.nz
FERTILISER October/November: Late spring. Frost over. Start summer crops now. Plants need water, light and minerals. They soon die without water (life’s chemistry is in water). Death from darkness/shade takes longer (no energy). Death from mineral deficiency takes longer still (but is just as sure).
Mineral deficiency: Without access to a cocktail of minerals dissolved in the soil water, a plant’s internal chemistry goes awry. Malnourished plants are vulnerable to pests and diseases. In this case, the symptoms are pests and diseases but the underlying problem is malnutrition. Same with malnourished children…
CEC: Our sandy Eastbourne soils are low in mineral nutrients. This because of sand’s very low cation-exchange capacity (CEC). Soil minerals are quickly washed down below the rootzone. Increase CEC by increasing the dead plant material in the soil – spread/dig-in compost, surface mulch with tree chip.
Increase-maintain: But raising CEC means only that soil minerals will be lost more slowly. You must also add minerals to raise/maintain soil mineral status. Also keep adding soil minerals to replace those lost when plant materials leave your property (e.g. as food, greenwaste).
Minerals: The ‘macronutrients’ are the minerals required in largest amounts - nitrogen (N), phosphorus (P) and potassium (K). Meanwhile, calcium, sulphur and magnesium are also required in fairly large amounts.
•The ‘micronutrients’ (also called ‘trace elements’) are iron, boron, chlorine, manganese, zinc, copper, molybdenum and nickel. •These micronutrient minerals are just as essential for healthy plant growth as the others - but are required only in tiny amounts.
Fertilisers: Garden centres sell bags of general fertiliser that contain the macronutrients N, P and K. Sometimes these also contain the micronutrients. •Get the bag with the added micronutrients (trace elements). •Your sandy soil will have low CEC, so fertilise little and often. •A ‘slow-release’ formulation does this for you.
Worried? If you worry about using a fertiliser made with ‘mined’ minerals you can buy ‘natural’ animal-based fertilisers (e.g. sheep pellets, blood and bone), or plant-based fertilisers (e.g. seaweed). •Unfortunately, the amounts of N, P and K in these 'natural' products vary very widely. Also, the amounts of the micronutrients. Quality control is difficult/impossible with a 'natural' product. •I would still buy a bag of a commercial micronutrient (trace element) product.
Last: You can’t know exactly how much of each mineral you need without expensive soil tests. •But better to use some fertiliser (do what the label says) than none. Also... •The addition of micronutrients (trace elements) could well address a critical deficiency in your sandy Eastbourne soil…___________________________________
FERTILISER October/November: Late spring. Frost over. Start summer crops now. Plants need water, light and minerals. They soon die without water (life’s chemistry is in water). Death from darkness/shade takes longer (no energy). Death from mineral deficiency takes longer still (but is just as sure).
Mineral deficiency: Without access to a cocktail of minerals dissolved in the soil water, a plant’s internal chemistry goes awry. Malnourished plants are vulnerable to pests and diseases. In this case, the symptoms are pests and diseases but the underlying problem is malnutrition. Same with malnourished children…
CEC: Our sandy Eastbourne soils are low in mineral nutrients. This because of sand’s very low cation-exchange capacity (CEC). Soil minerals are quickly washed down below the rootzone. Increase CEC by increasing the dead plant material in the soil – spread/dig-in compost, surface mulch with tree chip.
Increase-maintain: But raising CEC means only that soil minerals will be lost more slowly. You must also add minerals to raise/maintain soil mineral status. Also keep adding soil minerals to replace those lost when plant materials leave your property (e.g. as food, greenwaste).
Minerals: The ‘macronutrients’ are the minerals required in largest amounts - nitrogen (N), phosphorus (P) and potassium (K). Meanwhile, calcium, sulphur and magnesium are also required in fairly large amounts.
•The ‘micronutrients’ (also called ‘trace elements’) are iron, boron, chlorine, manganese, zinc, copper, molybdenum and nickel. •These micronutrient minerals are just as essential for healthy plant growth as the others - but are required only in tiny amounts.
Fertilisers: Garden centres sell bags of general fertiliser that contain the macronutrients N, P and K. Sometimes these also contain the micronutrients. •Get the bag with the added micronutrients (trace elements). •Your sandy soil will have low CEC, so fertilise little and often. •A ‘slow-release’ formulation does this for you.
Worried? If you worry about using a fertiliser made with ‘mined’ minerals you can buy ‘natural’ animal-based fertilisers (e.g. sheep pellets, blood and bone), or plant-based fertilisers (e.g. seaweed). •Unfortunately, the amounts of N, P and K in these 'natural' products vary very widely. Also, the amounts of the micronutrients. Quality control is difficult/impossible with a 'natural' product. •I would still buy a bag of a commercial micronutrient (trace element) product.
Last: You can’t know exactly how much of each mineral you need without expensive soil tests. •But better to use some fertiliser (do what the label says) than none. Also... •The addition of micronutrients (trace elements) could well address a critical deficiency in your sandy Eastbourne soil…___________________________________