Impact of water harvesting techniques and nutrient management options on the yield of pearl millet in the Sahelian Zone Of Mali

Low inherent soil fertility as well as inappropriate water and nutrient management practices are the major constraints to pearl millet productivity in the Sahelian zone of Mali. In order to increase the productivity of millet in Mali, the current research was conducted at the Agricultural Research Station of Cinzana, Mali during the rainy seasons of 2013 and 2014. The objectives of the study were to determine the effect of water harvesting techniques and nutrient management options on: (i) growth and yield of pearl millet, (ii) soil moisture content and rainwater use efficiency, (iii) partial N and P balances and nutrient use efficiency. The cost effectiveness of water harvesting techniques and nutrient management options were also ascertained. The water harvesting techniques evaluated were zai, tied ridge and conventional tillage (control). Cattle manure was applied at 0 and 2500 kg ha-1, while mineral fertilizer was applied at 0, 20.5 kg N: 23 kg P2O5 ha-1 and 41 kg N: 46 kg P2O5 ha-1. Experimental design was split – plot with randomized complete block design. The results showed that the pearl millet grain yield increased from 47 to 67 % under zai, 31.37 to 53.00 % under tied ridge as related to conventional tillage. Manure application improved pearl millet grain yield by 29 to 45 % over the control. The mineral fertilizer application increased pearl millet grain yield by 34 to 54 % compared to the control. The combined application of 41 kg N: 46 kg P2O5 ha-1 + M 2500 kg ha-1 increased grain yield from 1370 kg ha-1 in 2013 to 1716 kg ha-1 in 2014, while the increases in the control were 433 kg ha-1 in 2013 to 846 kg ha-1 in 2014. Straw yield of pearl millet increased by 30 to 41 % under zai and 25 to 37 % under tied ridge as compared to the conventional tillage. Combined application of manure and mineral fertilizer improved straw yield on average by 23.37 to 35.00 % and 18.80 to 27.17 %, respectively over the control. Manure had a higher (27.77 %) harvest index than the control (23.85 %) in 2013 cropping season. The mineral fertilizer application recorded the highest value of harvest index (28.10 %) compared to the control (22.01 %). Application of manure and mineral fertilizer improved N and P agronomic efficiencies. Soil moisture content significantly improved with water harvesting techniques. Zai recorded the highest value (52.06 mm) of soil moisture stored followed by tied ridge with 47.16 mm and the lowest value (39.48 mm) obtained under conventional tillage within the 20 – 40 cm depth at 45 days after sowing. Manure application increased soil moisture stored in both depths as compared to the control. The rainwater use efficiency recorded under zai and tied ridge were 3.45 and 3.17 kg grain mm-1, respectively as compared to the 2.06 kg grain mm-1 under conventional tillage. Manure application increased RWUE by 33.00 % as compared to the control, while mineral fertilizer improved RWUE by 31.64 to 35.00 % over the control. In the 2014 cropping season, nitrogen uptake by grain was 26.00 and 52.75 % higher under tied ridge and zai pit, respectively than conventional tillage. In the 2014 cropping season, phosphorus uptake by grain was 57 and 71 % higher under tied ridge and zai pit, respectively than the control. In both years, the application of manure at 2500 kg ha-1 and mineral fertilizer at 41 kg N: 46 kg P2O5 ha-1 led to positive partial P and N balances. The most cost effective water harvesting technique was the tied ridge, while the application of mineral fertilizer at 20.5 kg N: 23 kg P2O5 ha-1 with 2500 kg ha-1 of manure gave the highest returns on investment. Consequently, the use of tied ridge and mineral fertilizer at 20.5 kg N: 23 kg P2O5 ha-1 with 2500 kg ha-1 of manure could be an appropriate option for improving millet productivity in Mali.

Source: KNUST