Plants require nitrates for growth. To maximise crop yield, farmers utilise techniques such as crop rotation and ploughing of fields prior to planting their seedlings. Explain how the two techniques mentioned improve plant yield:

Plants require nitrates to be up-took via active transport for conversion to amino acids which are used to make proteins for growth. To increase yield, farmers need to increase the nitrates available in the soil for plant growth.Ploughing fields increases air and hence oxygen for aerobic nitrifying bacteria which convert ammonia (from decomposed waste) to nitrates.Ploughing fields is unfavourable for aerobic denitrifying bacteria which convert nitrates to nitrogen gas, which is useless for plants.Crop rotation means that the soil is less likely to become depleted in one particular type of nutrient. Crop rotation often includes a cycle of legumes e.g. peas - their root nodules contain nitrogen-fixing bacteria which convert nitrogen in the air to nitrates.