Cropkare contains the full range of trace elements needed by crops and grass. In crops, deficiencies of manganese, boron and copper are most common. Grass rarely suffers from trace element deficiency but the herbage may contain too little copper and selenium to meet livestock needs.

The trace elements supplied by a typical application of 500 kg/ha meet, or exceed, the amounts removed by most crops.

 

Content (ppm in Cropkare)

Every 100 kg of Cropkare supplies (g/ha)

9 t/ha wheat grain typically removes (g/ha)*

7 t/ha silage DM typically removes (g/ha)**

Boron

98

10

 

70

Copper

291

29

70

20

Iron

4500

450

550

500

Manganese

1800

180

350

800

Molybdenum

11

1

 

5

Selenium

3

0.3

0.2

1.2

Zinc

1662

166

50

150

* Soil and soil fertility. Troeh, F R and Thompson, L M.  Blackwell Publishing, 2005. Evidence of low selenium concentrations in UK bread-making wheat grain. Adams, M L, Lombi, E, Zhao, F and McGath, S P (2002). Journal of the Science of Food and Agriculture, 82, 1160-1165.

** Nutrient elements in grassland. Whitehead, D C. CABI Publishing, 2000.

Manganese

Manganese is involved in chlorophyll formation and enzymatic control of oxidation – reduction processes, and in some ways is similar to magnesium. Manganese deficiency appears as pale yellow mottling on the most recently matured leaves in cereals, maturity is delayed and ear emergence reduced with a high incidence of blind ears in potatoes the symptoms are discrete brown/black spots along veins of young potatoes. Brassicas show chlorotic marbling. Usually seen in patches across a field, deficiency is aggravated by wet, cold conditions and high pH, peaty and sandy soils liming and cropping old pastures.

Copper

Only small quantities are needed and the function of copper in the plant is uncertain, but it is associated with enzymes and is a constituent of chloroplasts and aids the stability of chlorophyll. Copper deficiency can be seen as a spiralling of younger leaves and a shrivelling of leaf tips in cereals. Deficiency frequently occurs following nitrogen application and on peaty and sandy soils. Ears show blind grain sites or poor grain formation.

Boron

Adequate Boron is essential for good storage quality in root crops. Boron deficiency is often linked to ‘lock up’ of nutrient due to high soil pH conditions. A deficiency has not been found in UK cereals or grass, but occurs commonly in toot crops, legumes and leafy brassicas. Serious deficiency causes lengthwise cracking of main and secondary stems and leaf petioles with poor flowering, reduced pod set and pod fill and uneven maturity in oilseed rape crops. Sugar beet deficiency symptoms show patchy leaf yellowing with the texture of older leaves becoming rubbery. Growing points die and failure of lateral buds to develop shoots. Leaves may become thickened and sometimes curl.

Zinc

Zinc deficiency shows as parallel yellow bands at either side of the leaf midrib. In wheat this is followed by necrotic blotches and in barley it is followed by orange/brown blotches.

Selenium

Selenium is an essential trace element for all animals. In dairy cows selenium deficiency causes problems of sub fertility, retained placenta, increased milk cell counts and increased levels of clinical mastitis. In beef calves deficiency is associated with ‘white muscle disease’. Raising the concentration of selenium in the grass can have a greater effect of increasing selenium in the blood and preventing deficiencies than providing it in feed supplements

Iron

Iron is essential for the proper functioning of chlorophyll and related photosynthetic activity. Iron uptake is strongly related to soil pH, and some species, such as sugar beet, brassicas and beans, can show lime-induced iron deficiency, particularly where soil aeration is poor.