1 Aerators reduce the manure nitrogen content, require fairly high capital investment, and are expensive to operate and maintain.
2 If it were not for oxygen and nitrogen in the air, no man could live on the earth.
3 They'd been pumping liquid air and nitrogen into the submerged tanks of the platform to try to stabilize it but, with steep waves, they were fighting a losing battle.
4 They'd been pumping liquid air and nitrogen into the submerged tanks of the platform to try to stabilize it.
5 Most fertilizers contain nitrogen and phosphates.
6 The faeces contain nitrogen and it is that which fertilises the desert soil.
7 Liquid nitrogen boils at a very low temperature.
8 Visually healthy fields may be the result of high nitrogen levels in leaves because there are fewer pods to fill with soybeans.