Farimah Omidi - Ph.D Candidate, Water Engineering Department, Agriculture and Natural Resources Campus, Tehran Science and Research Branch, Islamic Azad University, Iran,
Mehdi Homaee - Professor, Department of Soil Science, Tarbiat Modares University, Tehran, Iran,

Frequent droughts in arid and semi-arid climates such as Iran’s not only reduced the amount of available water for agriculture but also lessen the quality of water and soil nutrients. Today, considering the environmental and climatic situation, using saline water along with deficit irrigation and fertilizers in order to maximize the productivity is trendier than ever. The objective of this research is to assess the effects of water, salinity and nitrogen stresses on green pepper (Capsicum Annum) yield through crop production functions. Regarding the objective, the experiment schedule conducted for green pepper as complete accidental blocks in a green house. The experiment was implicated in a 42 days period for 108 pots in 2014. In this experiment, 4 irrigation treatments, three irrigation water salinity treatments and three nitrogen fertilizer treatments were designed. After harvesting, the amount of yield containing fruit, foliage and roots was weighed for each pot and then the amount of produced dried matter was measured. At the end, conjoined crop – water – salinity – nitrogen production function was conducted. Resulted crop production function can indicate the quality and quantity of environmental stresses on crop yield.

deficit irrigation; nitrogen; saline water; greenhouse; dry matter