Managing Director Mark Law of Laws Fertilisers, one of the few independent fertiliser manufacturers in the country often at the forefront of new technologies, reports that the company has developed positive strategies for farmers to prepare for dry spring and early summer periods.
"The overwhelming evidence from the scientific community across the world is that climate change is an inevitable consequence of 150 years of industrialisation which will lead to more extremes of weather. After one of the coldest winters on record we are facing a significant period of drought at a critical time in the life cycle of winter crops. East Anglian crops grown in light soils, which are poor at holding moisture, combined with the rain shadow effect from the rains brought by the prevailing winds from the west, are suffering particularly badly," he says.
"Our nutrient strategy encourages rapid and strong early establishment of crops by ensuring very soluble fertilisers are placed close to the developing seed. Then by using different types of nitrogen, the acidifying effect of ammonium ions in particular, leads to crops needing only half the amount of moisture of plants grown with normal nitrogen through the plant being able to grow with lower transpiration rates (water loss from the leaf)," claims Mark.
"The use of some nutrients can also modify the ability of the leaf to counteract extreme weather. Alkaline cations applied in the topsoil for sugar beet will improve the quality of the plants’ leaf by increasing the number of stomata (holes on the underside of the leaf) such that the leaf can regulate water loss during drought with greater precision."
According to Mark, with dry soils and roots being unable to absorb nutrients in solution, farmers should consider the use of foliar feeding to maintain a green plant. "Nutrients such as nitrogen would maintain the growth of the plant whilst other nutrients can increase the osmotic potential of the plant so increasing the ability to absorb moisture from both the soil and air."
Laws has also undertaken some pioneering work in trace elements which are nutrients that are only required in very small quantities for good plant growth. "However as Leibigs Law of the mid 19th century stated the crop is limited by the essential nutrient which is limiting, such that despite a crop having ready access to nitrogen, phosphate and potash a shortage of a nutrient such as boron can have catastrophic effects."
Laws does not only review all the 13 elements that are vital for plant growth but also some trace elements such as manganese which are the building blocks of anti oxidants such that in periods of stress, such as drought stress, super fertilisation by manganese will enable the plant to cope better than plants with just an adequate supply rather like vitamin C in humans to prevent colds.
Mark explains that in all cases when a plant in the second half of its life cycle starts to lose green leaf there tends to be internal plant processes that start to prepare the plant for the end of its life which are very difficult to reverse. "This is the stage of many crops today as the drought continues, but if the rain forecast imminently arrives most crops are likely to recover. If that is not the case then it would be well worth farmers without access to plentiful irrigation resources to consider an emergency foliar feed and consider both a review of the whole fertiliser programme and strategies to improve cultural techniques to maximise root size and improve root shape."
If growers would like further information about effective nutrition under drought conditions Laws will be at Cereals on the 9th-10th June or they can contact Mark Law, Managing Director, Law Fertilisers Ltd directly on 01354 740740 or on 07710 324463 (mobile) or via e-mail mlaw@lawfertilisers.co.uk
