The effect of cultivation systems on water availability and soil organic matter under winter wheat in Ireland

Conservation tillage has an important role to play in protecting soil quality, reversing soil degradation and maintaining and increasing crop yields into the future. A key factor driving crop yield is the availability of soil water for crop uptake. Traditional (inversion plough based) tillage systems impair soil quality over time by reducing soil organic matter (SOM) levels and damaging soil structure. Well-structured soils hold and conduct the water, nutrients and air necessary for healthy plant root activity and if structure is damaged, there is reduced rainwater infiltration (RWI) and lower water holding capacity (WHC) which restricts water available for root uptake and reduces crop yield. Lower intensity conservation tillage systems are less damaging to soil structure compared to traditional systems and supports the activity of soil organisms and roots which helps rebuild the structure. This study examined the soil volumetric water content and soil organic matter levels under a crop of winter wheat (Triticum aestivum ‘Graham’) under four different cultivation systems in the first year of establishment. The systems were: plough, min till (deep) min till (shallow) and no till. The results shows that the No Till plots showed consistently highest moisture levels compared to other systems and significantly higher average monthly volumetric moisture than plough in every month of measurement. Even after a single growing season the No Till system already showed significantly higher crop water availability than the traditional plough-based system. The No Till system also showed a trend for numerically higher levels of SOM. How we manage our soils in the future will have a massive impact on our soils capacity to deliver the future global food requirements.