2017 Grazing Season Review

Published 3 November 17

Following a challenging year for managing grass growth in 2016, 2017 bought strong grass growing conditions but also difficult management scenarios for many. Total average grass production across our Forage for Knowledge (F4K) this year was approximately 200kg DM/ha greater than the 2016 average, with the 17 F4K farms producing, an average, 14.1 t DM/ha. 

Grass Growth Curve

Figure 1: Seasonal grass growth curve

Following a dry and mild winter, grass growth rates were off to an exceptionally good start. With the warmest March reported since 1957 growth rates accelerated until Mid-April with 41% more grass produced in April compared to last year.

2017_4_Mean Temp _Actual2017_4_Mean Temp _Anomaly _1981-2010

Figure 2: Mean Temperature April 2017 in comparison with 1981-2010 anomaly. Source: Met Office.

A cooler end of April, with numerous late frosts, matches the decline in grass growth to levels more consistent with previous years until mid-May. The brighter showery weather experienced in mid-May accelerated growth, with the average daily growth rates of 91.7 kg DM/ha recorded in early June. The first part of June bought significant amounts of rainfall to most of GB resulting in a decline in growth and grass utilisation. Growing conditions altered and an overall incline trend was seen from July to mid-August before declining into an unsettled September. Unusually high number of rain days combined with lower than normal amount of sunshine resulted in average growth rates of 54.2 kg DM/ha/day noted.   

2017_9_Sunshine _Anomaly _1981-20102017_9_Rainfall _Actual

Figure 3: Sunshine duration and rainfall amount for September 2017. Source: Met Office. 

October saw temperatures 1.5-2.0°C higher than the long-term average which helped maintain good growth rates. The colder brighter weather towards the end of the month was followed with a widespread of ground frost resulting in a decline in growth rates. Average daily growth declining, down 16.68 kg DM/ha to 25.6 kg DM/ha this week, mirroring the rates reported in early November 2016.

Grass Quality

A testament to the management of the F4K farmers, grass quality has remained good over the course of the grazing season with Dry Matter (DM), Crude Protein (CP) and Metabolisable Energy (ME) averaging 17.3%, 23.1% and 12.0 MJ/kg DM respectively. Grass CP content remained relatively comparable with the long-term average following a relatively normal pattern as the year progressed. High CP levels in the latter part of the season most likely reflect the good soil temperatures we have seen throughout September and October which has meant soil nitrogen mineralisation rates remain high. As expected, there is a steady seasonal decline in grass DM content. ME levels were almost unchanged through the season, still averaging 12.0MJ kg/DM on 20 October. On average ME was 0.3 MJ/kg DM higher throughout 2017 in comparison to 2016.

Figure 4

Figure 4: 2017 grass quality

Forage for Knowledge grass growth monitoring will be starting again in February 2018. If you are interested in becoming a Forage for Knowledge farmer, please don’t hesitate to get in touch.