Soil provides a reservoir of nutrients required by crops, and therefore animals, but not necessarily at optimum levels of immediate availability to plants. The purpose of soil analysis is to assess the adequacy, surplus or deficiency of available nutrients for crop growth and to monitor change brought about by farming practices. This information is needed for optimum production, to avoid transferring undesirable levels of some nutrients into the environment and to ensure a suitable nutrient content in crop products. Farm assurance schemes, buyer’s protocols and codes of practice are increasingly demanding more accurate fertiliser recommendations which must depend on the nutrient-supplying capacity of the soil. Regular soil analysis, every 3-5 years, should be undertaken as a vital part of good management practice. Read More…

The major role of sulphur in all plants is in support of nitrogen in protein production which is hugely important for high crop yields. For breadmaking wheat, protein production and its quality are even more important for loaf volume. In brassicas, (veg, oilseed rape, kale etc) sulphur is also in glucosinolate compounds, which give them their hot taste. Sulphur also reduces the likelihood of immature rapeseed which faces penalty pricing in the market. This explains the greater requirement and importance of sulphur applications to brassicas. In grass, sulphur is probably more important for improving the quality of grazing and silage, in terms of protein, than the yield increase achieved. Read More…

Sulphur in the soil acts in a similar way to nitrogen. It is released from the breakdown of organic matter, and to some extent from soil minerals. Soils which are organic, or heavy textured are more able to supply adequate sulphur than light and inorganic soils. Organic sulphur in the soil comes from organic matter, whether from applied organic materials or from grazing/crop residues. The organic sulphur must be “mineralised” into the sulphate ion (SO₄^2-) to be taken up by plants. These sulphate ions reside in the soil solution which means they are liable to be leached, depending on the soil texture and rainfall, just like nitrates. This risk must be considered when nutrient planning. Read More…

Nutrient stratification refers to the accumulation of nutrients in differing concentrations down the soil profile. This can occur through applications of fertiliser and manure to the soil surface, or simply through crop growth, as plant roots scavenge deep into the soil profile for nutrients which then accumulate in plant material and senesce as the plant matures, leaving residues on or close to the soil surface, releasing nutrients back to the soil as they decompose. Read More…

Calcium is responsible for proper plant cell division and strengthening cell walls giving them rigidity and strength. It also improves the absorption of other nutrients by roots and their translocation within the plant. It activates many plant growth-regulating enzyme systems, helps convert nitrate-nitrogen into forms needed for protein formation and contributes to improved disease resistance. It also plays a role in regulating various cell and plant functions. Read More…

The main roles of magnesium in plants are in the formation of chlorophyll and of enzyme activators. Photosynthesis, protein formation and energy transfer all depend, in part, on an adequate supply of magnesium. It is taken up by plants as the ion Mg²⁺ and is mobile once in the plant, so can move from older to younger tissues. Deficiency therefore tends to be seen first in the older leaves when the concentration in the dry matter falls below 0.2% Mg. Read More…

Potash enhances the development of strong cell walls and therefore stiffer straw. Lodging is affected by obvious factors such as variety, nitrogen rate and weather, but low potash levels also increase the risk of lodged crops with the associated loss of yield and quality. The effect can be as dramatic as a lack of growth regulator in some circumstances. Read More…

Physiological stress will be more damaging if potash nutrition is limiting – frost damage will be more severe, waterlogged areas will take longer to recover, and plants will wilt earlier and remain flaccid for longer under drought conditions. Crops will be more susceptible to disease and pests especially where nitrogen and potash availability are imbalanced. This will result in weaker, sappier growth which will contain a higher concentration of soluble nitrogen compounds and simple carbohydrates providing a readily available food source and attractive focus for pathogens and insect pests such as aphids. Read More…