In order to properly valorize date palm waste as compost and biochar to improve soil fertility in the arid region, we carried out a trial in vegetation pots with a capacity of 5kg with a barley crop 8 plants/pot, using different combinations of compost and biochar.

The treatments used are: T: Control (without amendment), C1: 100g of compost/pot, C2: 150g of compost/pot, B1: 17g of biochar/pot, B2: 34g of biochar/pot, C1B1 : 100g of compost +17g of biochar, C1B2 : 100g of compost + 34g of biochar, C2B1 : 150g of compost + 17g of biochar  and C2B2 : 150g of compost + 34g of biochar.

The results obtained show that the highest dose of compost C2 gives the best results in grain yield 10.6g and weight of 1000 grains 42.33g, while the combination of the small dose of compost with the highest dose of biochar C1B2 gives the highest plant height 47.34cm and the highest straw yield 13.66g. This combination gave a high organic matter OM content 3,79%  and the lowest pH of the soil 7.4  as well as an acceptable electrical conductivity EC. It should also be noted that the C2B1 treatment gave high grain production, while the C1B1 treatment gave high straw production.

It can be concluded that the highest dose of compost C2 can give better results in terms of grain production, while the compost-biochar combination C1B2 is preferable for biomass production.

Keywords: compost, biochar, barley, soil, plant