The soils of Algeria are generally poor in nitrogen and always pose the problem of the availability of available phosphorus especially in arid regions, where there is also the problem of salinity which is often accompanied by the presence of limestone. The present work aims to examine the optimization of phospho-nitrogen fertilization on a durum wheat crop in saline and carbonate conditions through the use of different types, forms and doses of nitrogen and phosphate fertilizers. The fertilizers used are: Urea(46%), triple super phosphate TSP(46%), simple super phosphate SSP(20%), Potassium Nitrate KNO 3 (13%), Monammonium phosphate MAP(12%, 61%), NPK(15%,15%,15%), NPK(20%,20%,20%), NPK(13%,40%,13%), NPK(30%,10%,10%), NPK(4%,20%,25%), combined with three doses (D1=150U N and P ha -1 , D2=200U N and P ha -1 and D3=250U N and P ha -1 ). The results obtained show that phospho-nitrogen fertilization has a very important effect on the parameters studied. Indeed, we notice that the best results are obtained by compound fertilizers, height of the plants: (HP) =MAP and NPK(15%,15%,15%) (250U ha -1 ) and (KNO 3 -SSP) (150U ha -1 ), yield and its components: Number of grains ear -1 (NG E -1 ) =NPK(13%,40%,13%) (250U ha -1 ), 1000 grains weight (TGW) =NPK(4%,20%,25%) (250U ha -1 ), grain Yield (GY) =NPK(13%,40%,13%) (250U ha -1 ) and NPK(15%,15%,15%) (150U/ha), straw yield (SY) =NPK(15%,15%,15%) (250U ha -1 ) and (KNO 3 -SSP) (150U ha -1 ). However the highest nitrogen and phosphorus content of the grains is obtained by simples fertilizers, N= (Urea-SSP) with the dose (200 and 250 U ha -1 ), and P = (Urea-TSP) with the dose (150U ha -1 ). It is noted that the NPK(15%,15%,15%) fertilizer was able to give better grain and straw yields with the lowest dose as well as obtaining the best plant height and better straw yield with the lowest dose of (KNO 3 -SSP) fertilizer.