Matching the crop (and variety) to the soil type can improve crop vigour and biomass production, which in turn will optimise crop competitive ability. Crops growing in unsuitable soils are far more susceptible to disease and insect attack. Poor early vigour can also result from crops grown in unsuitable soils. The slow crop growth is also advantageous to the weed. Nodulation of pulses can be reduced, thus decreasing plant biomass and competitiveness.
For example, on very acidic soils (pH less than 4.5) grow narrow-leaf lupins, triticale or acid tolerant wheat as these are more suited than other crops to such soils. On heavy soils that suffer periodic waterlogging during early winter, the best suited break crop is faba bean. Sowing equipment should be tailored to suit soil properties to obtain the highest plant count in the shortest time. In heavy clay soils press wheel pressure may need to be increased as the soil dries.
Improving soil constraints to plant growth (eg acidity, salinity, sodicity, boron toxicity) can dramatically improve crop growth. For instance the use of lime on acidic soil suppresses weed growth and improves crop yields. Also of importance are the levels of beneficial soil microbes such as vesicular arbuscular mycorrhiza (VAM) as well as environmental conditions including soil properties and rainfall.
Article: CulturalWeedControl175 (permalink) Date: 9 January 2013; 7:50:11 PM AEDT