By: Sean Sparling, Independent Agronomist and Chairman of the AICC
From what started as a persistently wet winter through to the driest summer on record, we saw all the extremes of wet and dry, cold and heat through the 2018 harvest season, yet yields were not all as disastrous as it was feared.
Good soil structure has always been the key to maintaining crops through extremes of weather, because they build good root systems and, in order for plants to be able to access crucial nutrients as the season progresses, both the free movement of water in wet times and the plants ability to access water reserves in dry times are vital.
Through the winter of 2017 into early spring this year, we experienced several months of weather which, although not the wettest we have seen, was the least dry. By that I mean that almost every day we took a little rain, leaving very few dry days to dry out the land. From the 15th October 2017 to the 15th April 2018 I recorded just 40 days where I registered no rainfall at all, and only once in that 182-day period did I register more than 2 consecutive dry days – fields just sat wet.
Crops on well-structured soils produced and maintained robust fibrous root systems and efficiently distributed the water through the profile. But the poor structured soils remained saturated, meaning these crops sat with their roots in water for months, causing the essential fibrous roots to rot away in the almost anaerobic conditions.
Once winter passed into spring and summer, and when the hot dry months hit, with just 85mm rain in the 123 days from 1st May to 1st September – and with 101 of them dry – the well rooted crops thrived in the constant and increasing warmth. However, those crops with fibrous root systems that had degraded over the wet winter, couldn’t seek out water or support their canopies and so they suffered badly and droughted out. From the 1st May 2018 to the 10th October 2018, just 110mm of rainfall was recorded here, compared to 338mm in the same period in 2017.
Rainfall was very localised over the summer – some fields on the same farm receiving 50mm plus in a couple of hours, whilst others half a mile away had nothing at all. This meant that if farms were fortunate enough to get rain at key times, they withstood the hot dry conditions well, so across the UK, where the rain came at key times, which in many areas it did, farmers saw a very positive harvest both in terms of yield and quality.
The overall disease risk proved to be lower too due to the drier conditions – but that too was not straightforward.
We were still faced with the usual issues with the key diseases, but these diseases too adapted to the very different circumstances. Yellow rust for example used to be a cool wet weather disease, yet it seemed to thrive in the hot dry conditions usually associated with brown rust proliferation. Septoria tritici also adapted and in the absence of rain splash, it too spread easily in lush canopies via the dew and when wind thrashed leaves touching each other in the windy conditions.
Variety choice also proved key – with newer cereal varieties such as Kerrin, Siskin, Gravity and Graham thriving in the hot dry conditions. As a result, there has been much less variation in yields in the newer varieties compared to older varieties – with up to 5 t/ha difference between old and new cultivars on the same farm.
Whether you were farming on heavy clay, brash, silts, sands or loamy sandy soils, the performance of crops at harvest 2018 depended ultimately upon soil structure and land management.
Irrespective of soil type, the 2018 harvest was best on the well managed soils, that are well-structured and free draining. Once again that bit of luck, or good management, was the key to success!
Sean Sparling is a multi-award-winning independent agronomist walking 25,000 acres of Lincolnshire farmland advising on all aspects of crop production. Sean is Chairman of the Association of Independent Crop Consultants (AICC), which is the professional body of the largest group of independent crop consultants in Europe. With 262 members, well over 80% of all independent agronomists in the UK are members of the AICC and the total independent advice sector including AICC, provides advice to almost 50% of the UK arable market.
The Crop Establishment Seminar will be held at this year’s CropTec Show. Central to the discussion will be the improvement of soil health, particularly when cultivation needs to take place in challenging conditions, as we have experienced over the past 12 months.
The crop establishment seminar stream is sponsored by Certis and Horsch.