1(kamlesh@agfe.iitkgp.ernet.in)
4Precision Farming Development Centre Project, Agricultural and Food Engineering Department, I.I.T., Kharagpur-721302
Among various inputs, the modern agriculture is heavily dependent on the use of fertilizers and pesticides to meet the food requirements of ever-increasing population. Nitrate form of nitrogen is one of the major plant nutrients, and is mainly responsible for the pollution of soil and water resources. The movement of nitrate-nitrogen (NO3-N) in the soil is a complex, but largely affected by water movement. An attempt was made to study the dynamics of NO3-N under sub-surface drip irrigation in potato (Kufri-jyoti) crop. Four levels of fertilizer-N were applied at two depths of application with subsurface drip. The nitrogen fertigation levels were 40%, 60%, 80% and 100% of the recommended dose and replicated three times. Irrigation water requirement of the crop was estimated using cumulative pan evaporation data. The soil samples from three depths (0–15 cm, 15–30 cm and 30–45 cm) of the crop field were collected for chemical analysis. The maximum concentration of nitrate content was at 100% fertigaton levels, followed by 80% N level. The biometric observations showed that application of 100% N fertigation through subsurface drip irrigation buried at 10 cm depth exhibited highest vegetative growth as compared to other N fertigation levels. The maximum yield of 23.84 t/ha was obtained under the same treatment, followed by 20.03 t/ha under the treatment 80% N. The economic analysis indicated highest benefit-cost ratio of 2.11:1 for the treatment 100% N (F4) followed by 1.64:1 for 80% N.
