Development and Dissemination of 4R Nutrient Stewardship Knowledge to Support Crop Production Intensification

The objective of the project is to develop a Nutrient Expert® (NE) tool for Moroccan farmers and extension specialists to implement appropriate nutrient management practices for wheat production. In the 2014/2015 cropping season, omission nutrient trials were established in four regions of Morocco: Abda (semi-arid region), Chaouia (intermediate semi-arid region), Fez (favorable rainfall area) and Tadla (irrigated area). In each region, 10 on-farm trials were planted with wheat (bread wheat and durum wheat) under five nutrient treatments including: an optimum treatment (OPT) with 76 kg N + 40 kg P₂O₅ + 50 kg K₂O/ha in Abda; 84 kg N + 42 kg P₂O₅ + 52 kg K₂O/ha in Settat (Chaouia); 93 kg N + 72 kg P₂O₅ + 87 kg K₂O/ha in Berrechid (Chaouia); and 128 kg N + 72 kg P₂O₅ + 90 kg K₂O/ha in Fez; 192 kg N + 108 kg P₂O₅ + 135 kg K₂O/ha in Tadla; OPT-N; OPT-P; OPT-K, a control (without fertilizers); and farmer fertilizer practice (FFP).

Maximum grain yields were 5.0, 6.2, and 7.8 t/ha, respectively in semi-arid, favorable rainfed, and irrigated areas with no significant difference between bread wheat (BW) and durum wheat (DW). In all the regions the maximum grain yield was obtained with OPT treatment. Without fertilizer application, grain yield decreased an average of 50% in rainfed areas and by 30% in the irrigated area in the case of BW and DW, with no significant difference between both species. The effect of N on grain yield was higher than those of P and K. On average, the omission of N reduced the grain yield by 35%, 56%, 37%, 40%, and 17% at Abda, Settat, Berrechid, Fez, and Tadla, respectively. Phosphorus and K have similar effects on grain yield. On average, the omission of P and K reduced the grain yield by 15%, 29%, and 13%, respectively in semi-arid, favorable rainfed area, and irrigated area. In Irrigated areas, omitting N, P and K had similar effects on the grain yield with an average yield reduction of 14% and 17% for BW and DW, respectively. The maximum grain yield under OPT treatment was 7 t/ha in the irrigated area of Tadla; however, the lowest grain yield was in Chaouia region with an average grain yield of 3.4 t/ha. Grain yields of wheat under OPT treatment were higher than FFP. Higher increases were observed in the favorable rainfed area and irrigated areas where OPT was an average of 1 t/ha higher than FFP; however, in semi-arid area this difference was less than 1 t/ha.