The main reason of high NO3 − concentrations in some groundwaters is the over application of fertilizer on surrounding agricultural land (Al-hadithi 2012; Aly et al. 2015b).
Over-application of fertilizers and pesticides, and misuse or overuse of veterinary drugs and feed additives have brought about numerous quality and safety hazards (although these inputs do lead to increased production when used judiciously).
However, over application of nitrogen fertilizers and loss of phosphate fertilizer due to soil erosion may result in some undesirable environmental problems such as increase of nitrate in water and eutrophication of water bodies [ 19].
Over application of phosphate fertilizers in modern agriculture contaminates waterways and disrupts natural ecosystems.
Transportation aside, agriculture's carbon footprint includes the natural gas and petroleum consumed to produce chemical fertilizers and pesticides, as well as the nitrous oxide released to the air due to over-application of those fertilizers.
However, over-application of Pi fertilizers has led to run-off of excess Pi into waterways damaging ecosystems [ 6- 8].
The use of reference strips, when implemented properly, can help prevent over-application of N fertilizer by identifying areas where plants have sufficient N or are so compromised in growth due to other reasons that further addition of N is not economical.
Over-application of N fertilizer has become a common practice in maize production systems and has led to nutrient imbalances and inefficient fertilizer applications, and has resulted in negatively impacting the environment [3, 15].
TPR has several advantages like higher yield potential, convenience in application of fertilizers and pesticides, control of weeds, etc.
Operators can reduce costs per unit of production and increase the margin of return over total cost by increasing rates of application of fertilizer on principal cash and feed crops.
For one thing, Abell explained, it would make the application of fertilizers and herbicides far more precise.
