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

The objective of this 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 2016-2017 cropping season, nutrient omission trials were established in four regions of Morocco: Abda-Hmar (semi-arid region), Chaouia (intermediate-semi-arid region), Fez (rain-fed favorable area), and Tadla (irrigated area). At each region, 10 on-farm trials were planted with bread wheat (BW) and durum wheat (DW) under eight nutrient treatments: 1) optimum treatment (OPT) (84-36-45 kg N-P₂O₅-K₂O/ha in Abda-Hmar, 90-56-45 kg/ha in Settat (Chaouia), 99-65-50 kg/ha in Berrechid (Chaouia), 127-68-63 kg/ha in Fez, and 160-90-100 kg/ha in Tadla, (2) omitting nitrogen (N) from OPT, (3) omitting phosphorus (P) from OPT, (4) omitting potassium (K) from OPT, (5) control (without fertilizers), (6) site-specific nutrient management (SSNM) (according to Nutrient Expert recommendations), (7) Soil test (fertilization according to soil analysis), and (8) farmer fertilizer practice (FFP).

From the time of sowing to physiological maturity, the cumulative rainfall ranged from 193 mm in Hmar to 331 mm in Fez. Results of the study showed that the rain-fed areas of the Hmar region were less favorable for wheat production with an average grain yield of 0.8 t/ha and 1.3 t/ha, respectively for BW and DW. However in the Fez region, grain yields of wheat were the highest with an average of 3.4 t/ha with no significant differences between BW and DW. Among the three rain-fed regions, the highest response to macronutrient application was observed in the favorable region of Fez where omitted N, P, and K decreased the grain yield of BW by 17%, 14%, and 24% respectively, and the grain yield of DW by 38%, 32%, and 30%. In all the rain-fed regions, SSNM significantly increased the grain yield of wheat compared to FFP. In the irrigated area of Tadla, no significant difference was observed between the grain yield of DW and BW. For both species, the maximum grain yield was obtained with OPT treatment with 8.9 t/ha (BW) and 9.3 t/ha (DW). For both species, on average the omission of N, K, and P reduced the grain yield of wheat by 33%, 27%, and 20%, respectively. Similar increase of grain yields of BW and DW were obtained by the SSNM treatment compared to FFP, with an average of 1.5 t/ha.