S12 - Session P3 - The effect of crop cultivation systems on soil moisture availability

Authors: Mary Harty *, Gary Gillespie, David Hobson, Kevin McDonnell

Current food production systems are failing to feed the world with number of undernourished people estimated in 2010 at 925 million, higher than it was 40 years ago. To meet the estimated global food demand by 2050, current crop yields need to increase by an estimated 2.4% year on year. However, since the 1990's yields of many crops are stagnating. The combination of changing climates, deteriorating soil conditions and crop yields reaching their biological limits are thought to be the primary causes. Rainfed farming systems constitutes 80% of the world's cropland produce about 60 percent of the worlds cereal grains and is projected to produce one-third or more of the increase in global food output for the coming decades. Maximising resource capture is key to maximising yields. Inadequate soil moisture infiltration or retention may be limiting resource capture (water and nutrients) resulting in lower yield. An examination of the soil moisture content to 30cm over the growing season under four different cultivation systems for winter wheat was conducted. Results show (even in the first year of implementation) there were different levels of moisture availability under different cultivation systems at key times when crop is actively growing. The greatest differences in moisture availability occurred in driest periods, following ground rewetting. The moisture content of soil under the no-till cultivation system was consistently higher than all of the other treatments, followed by shallow and then deep-till systems and the ploughed system had lowest moisture level. This study has important implications for growers choice of cultivation system in the future to maximise crop yields in the changing rainfall conditions (less frequent and higher intensity) due to climate change.