Yield-limiting plant nutrients for maize production in northwest Ethiopia

Abstract

Summary The potential yield of improved maize varieties usually cannot be fully realised mainly due to inappropriate soil nutrient management practices in most parts of Ethiopia. Site-specific fertiliser recommendations are rarely used in the farming systems of Ethiopia. There is also a lack of data to develop or validate decision support tools for targeting specific crop production. A study was conducted for three consecutive rainy seasons (2016–2018) in the maize belt of the north-western parts of the Amhara National Regional State of Ethiopia. The objectives were to obtain the maximum achievable yield potential of maize, determine the most yield-limiting nutrients and create a database of maize responses to applied nutrients so that decision support tools could be developed for the study areas. Treatments were individual nutrients (nitrogen (N), phosphorus (P) and potassium (K)) and combinations of the three. In some treatments, NPK was also combined with sulphur, zinc, lime and compost. Two hybrid maize varieties (BH-540 and BH-660) adaptable to the study areas were used. BH-540 was used for the Mecha district, while BH-660 was used for the south Achefer, Jabitahnan–Burrie–Womberma districts. Maize yield increased by more than 50% due to fertiliser applications compared to without fertiliser. The study showed that the possibility of increasing maize productivity to more than 12 t ha-1 for the study sites. The most yield-limiting nutrient in the study sites was N, followed by P; K was not a yield limiting. Without N the yield of both varieties was non-significant from the control (without added nutrients). Maize grain yield did not respond to application of lime, compost, zinc and sulphur. The result also showed very high variability across sites, indicating that it is important for policymakers, farmers and investors to consider site-specific fertiliser recommendations. Finally, a database containing intensive plant response to NPK for maize was generated and could be used as input in site-specific decision support tools development.

Yield of potato (Solanum tuberosum L.) increased by more than two-folds through nitrogen and phosphorus fertilizers in the highlands of North-Western Ethiopia

“…Accordingly, the soils of Yilmana Densa were below the critical levels of SOC, whereas those of south Gondar ranged from below to critical levels ( Loveland and Webb, 2003 ; Murphy, 2014 ). It was similar with other findings for the cultivated lands of Ethiopia ( Amare et al., 2022a , 2022b ; Amare, 2018 ; Amare et al., 2013a , b ). Generally, soils of the study areas were low in SOC that limits the supply of nutrients including N and P ( Murphy, 2014 ).…”

“…(2019) also used the rates of N and P (138–151 N and 69–75 kg P 2 O 5 ha −1 ), which are similar to our findings and recommendations. In general, the yield of potato at Yilmana Densa could be improved by more than threefold (greater than 300%) and at South Gondar by more than two and a half-fold (greater than 250%) through nutrient applications (N) that is in line with the findings of Amare et al (2022a , b ), they reported that omitting nitrogen resulted in a non-significant yield of maize with no nutrient applications, regardless the high rates of phosphorus and potassium.…”

“…Ethiopian soils have been depleted because of negative input-to-output balances of the nutrients (low soil fertility) that could contribute to the high variability and low crop productivity, including potato ( Amare et al., 2013a , b , 2018 ; Amare et al., 2013a , b ; Hirpa et al., 2012 ; Kebede and Ketema, 2017 ; Muleta and Aga, 2019 ). Among plant nutrients, nitrogen (N) and phosphorus (P) are so far the most yield-limiting nutrients of cereal crops in Ethiopia ( Amare et al., 2018 , 2022a ), whereas for potato N is the most yield-limiting nutrient ( Muleta and Aga, 2019 ). However, the need to identify and update the biological and financial response of potato to N and P is a critical gap in north-western Ethiopia.…”

Response of tef yield and yield components to nitrogen and phosphorus fertilizers

“…This suggests that nitrogen is the primary limiting nutrient in the study sites, as nitrogen application had a more significant impact on yield compared to phosphorus. Amare et al [ 35 ] provided supporting evidence that nitrogen fertilizer is the primary and most significant yield-limiting nutrient, followed by phosphorus, confirming the idea that the decline in soil fertility affects crop production. Likewise, Alemayehu et al [ 36 ] and Chala et al [ 7 ] reported similar findings in their studies.…”

Identifying limiting nutrient(s) for better bread wheat and tef productivity in acidic soils of north‐west Amhara, Ethiopia

“…The responses to fertilizer application varied across geographical locations (Amare et al., 2018; Tamene et al., 2017) and environments. Fertilizer applications should consider landscape positions on soils with undulating topographic features (Amede et al., 2020).…”