Three Ways to. ... Detect Nutrient Deficiencies

According to this week's Torbay Herald Express:


1   Insufficient nitrogen can cause foliage to turn pale green and for the plants to become spindly.  Apply a high-nitrogen fertilizer to improve conditions 


I can think of two ideas for this:
Firstly, chicken poo pellets (as can be seen from RHS site http://apps.rhs.org.uk/advicesearch/profile.aspx?PID=297) they contain lots of nitrogen: 

Typical analysis of dried and pelleted poultry manure (can be variable):
N(nitrogen)         4%
P(phosphorus)    2%
K(potassium)     1%

"Happy to Help"

Secondly, leaving roots of peas and beans (legumes) in the soil after harvesting the legumes helps to fix nitrogen in the soil, using the nodules, see pic below (from : http://www.gardenhelp.org/food/nitrogen-fixing-root-nodules/)

2   Plants can develop yellow leaf edges spreading between the veins if they are short of iron.  This is most common on alkaline soils and you need to apply a product containing chelated iron (liquid or granular form) to ease the problems.

Chelated iron is a mixture of sodium, iron and a chelating agent to make the iron soluble in water and accessible to plants.  Perhaps this is why years ago old gardeners used to leave rusty bits of metal buried in their gardens (or were they just being untidy?!).  It can be purchased from garden centres and is also present in many general purpose fertilisers.

3   Lack of calcium - often experienced when plants are too dry to absorb it - causes distorted leaves, spots and cracks on fruit as well as blossom-end rot. Keep your plants moist to enable them to absorb calcium.

Remember - what my father told me years ago: 
Nitrogen (N): For green leafy growth
Phosphorus (P): For healthy root and shoot growth
Potassium (K): For flowering, fruiting and general hardiness


Ideas for problems and remedies from the excellent RHS (Royal Horticultural Society) site: http://apps.rhs.org.uk/advicesearch/profile.aspx?PID=456

Other essential minerals include:

Magnesium: to give green colour to leaves, with leaves turning colours such as yellow, purple, brown or red. Older leaves suffer first, and will die if they're not given any treatment. The nutrient can be leached out of light, sandy, acidic soil by high rainfall. or if there is too much potassium in the soil the plants absorb that instead of the magnesium.  As with our bodies, it's important to have a calcium/magnesium balance (eat plenty of bananas for potassium, that's why roses love banana skins).

For a long term solution, apply a yearly mulch of home-made compost.  This will conserve moisture, prevent the leaching of nutrients during heavy rainfall, and provide the soil with sufficient quantities of magnesium to keep the plants health.

An alternative is to apply Epsom Salts as a leaf spray for a quick, temporary solution in summer. Or Epsom Salts or calcium-magnesium carbonate can be applied to the soil in autumn or winter to remedy the deficiency for the next year.

(From: http://www.gardenersworld.com/how-to/problem-solving/magnesium-deficiency/)

For other minerals necessary in your soil there's an excellent site giving more information: http://www.gardensalive.com/article.asp?ai=57. For instance this pic shows strawberries deficient in boron: