Improving nutrient management knowledge in rainfed wheat cropping system of Algeria

This objective of this project, initiated in 2014, is to develop a Nutrient Expert® (NE) tool for Algerian farmers and extension specialists to implement appropriate nutrient management practices for wheat production in rainfed areas. During the 2014/2015 cropping season, three nutrient omission trials were established in the region of Tiaret, located in the north west of Algeria. Each on-farm experimental plot was planted with bread wheat (BW) and durum wheat (DW) with six nutrient treatments including: an optimum treatment (OPT) with 140 kg N + 60 kg P₂O₅ + 72 kg K₂O/ha for BW, and 120 kg N + 48 kg P₂O₅ + 68 kg K₂O/ha for DW; OPT-N; OPT-P; OPT-K; a control (without fertilizers); and farmer fertilizer practice (FFP). In all three sites, the previous crop of wheat was on fallow and the sowing dates were November 14 to 19, 2014. The sources of fertilizer were triple superphosphate, potassium sulfate, and urea.

The cumulative rainfall for the 2014-15 cropping season was 433 mm, which is less than the average rainfall in the region (550 mm). More than 90% of the precipitation was recorded between December 2014 and February 2015, and only 10 mm were recorded in the period between March to May 2015, which are considered as critical months for the growth and grain filling of wheat. The drought period that occurred in the middle and at the end of the season had a negative effect on the grain yield of wheat. Results showed that the average grain yield of wheat was less than the attainable grain yield of the region. The maximum grain yield was 3 t/ha for both BW and DW, obtained with the OPT treatment. The unfertilized check, or the omission of either N, P or K reduced grain yields of BW by 8 to 12% compared to the OPT. In the case of DW the unfertilized check reduced the grain yield by 16%, and N had a larger effect on the grain yield than P or K. Grain yield of DW was reduced by 12% in the absence of N, however the omission of P and K had no significant effects on the grain yield of DW. For both species, the grain yield under FFP was an average of 6% less than the OPT, and was not significantly different from the control. The project will continue for two more cropping seasons.