Iris Publishers - World Journal of Agriculture and Soil Science (WJASS)

Soil Fertility Management and Cropping System Function in Ameliorating Maize Productivity in Ethiopia

Authored by Derib Kifle

Maize (Zea mays L.) is the most important cereal worldwide [1] that belongs to the family Poaceae. It is a C4 plant, short duration and quick growing crop. It is globally ranks the third position among cereal crops after wheat and rice and it is important staple food in many countries. Grains of maize contain 13% moisture, 10% crude protein and 70.3 carbohydrates [2] is one of the most versatile emerging crops having wider adaptability under varied agro climatic conditions. Globally, maize is known as queen of cereals because it has the highest genetic yield potential among the cereals. Maize is cultivated throughout the world (58°N latitude to 40°S latitude) in an area of 179.9 m.ha across 165 countries with a production of 1013.6 m.t and average productivity of 5.63 t/ha. Only the USA, China and Brazil contribute 63% to the global maize production whilst Mexico, Argentina, India, Ukraine, Indonesia, France, Canada and South Africa are also major maize producing countries [3].

The major constraints affecting maize production and productivity are declining soil fertility and inadequate crop management practices, imbalanced nutrition, disturbed soil properties, cultivars being grown, weed infestation etc. [10]. Declining soil fertility is fundamental impediment to agricultural growth and a major reason for slow growth in maize production in sub-Saharan Africa [11]. Low soil fertility due to monoculture cereal production systems is recognized as one of the major causes for declining per capita food production [12]. Therefore, soil fertility replenishment is increasingly viewed as one of the critical to the process of poverty alleviation. This is generally true for Ethiopian agro ecologies, particularly for a dominant maize based mono cropping system of Ethiopia, which is one of the major problems leading to decline in soil fertility from time to time and resulting bottleneck for the smallholder maize producer of the country.

The use of inorganic fertilizers alone has not been helpful under intensive agriculture because it aggravates soil degradation. Maintaining and improving soil quality is crucial if agricultural productivity and environment quality are to be sustained for future generations. Intensive agriculture has had negative effects on the soil environment over the past decades (e.g. loss of soil organic matter, soil erosion and water pollution). management methods that decrease requirements for agricultural chemicals are needed in order to avoid adverse environment impacts. [13]. Sustainable crop production, therefore, requires Integrated soil fertility management involving the judicious use of combinations of organic and inorganic resources is a feasible approach to overcome soil fertility constraints. Combined organic/inorganic fertilization both enhanced carbon storage in soils and reduced emissions from nitrogen fertilizer use while contributing to high crop productivity in agriculture [14]

Improved cropping system which requires integration of legume crops in maize based mono cropping areas to add N- fixed through biological nitrogen fixation or biomass retentions [15] and a careful management of all nutrients sources available in a farm, particularly in maize based cropping systems which include inorganic fertilizers, organic manures, waste materials suitable for recycling nutrients, soil reserves, are immense in boosting maize production. All most all farmers in Ethiopia produce maize as continuous mono cropping or some of them as an intercrop with food legumes using the recommended 110 N kg/ ha and 46 kg/ha fertilizer for maize [16]. However, the price of inorganic fertilizer is getting beyond the purchasing power of smallholder farmers because of high production cost and uncertain accessibility in addition to non-responsiveness of some soils that leads the farmers to non-benefits. Therefore, inclusion of leguminous crops in cropping systems has multiple advantages in improving and sustaining maize productivity. Intercropping offers potential advantages for resource utilization decreased inputs and increased sustainability in crop production [17]. Therefore, the chief aim of this paper is to text existing information on the response of maize to integrated use of organic and inorganic fertilizer application and improved cropping system in Ethiopia. Accordingly, a review of the major findings on the response of maize grain yield to sole and integrated use of organic and inorganic fertilizer (integrated soil fertility management) and cropping system on the productivity of maize in Ethiopia.

Plant Nutrient and Soil Fertility Management in Maize Production

In the effort of alleviating the soil fertility problem which is one of the major causes of low productivity of maize, different research activities have been undertaken using various fertilizer sources in different parts of the country.

Sole and combined Use of Organic and Inorganic Fertilizers for Maize Production

Use of chemical fertilizers for maize production: Influence of chemical fertilizer (NP) on maize productivity in different parts of the country was reviewed and summarized by different researchers and scholars. The application of 75/33 kg N/P ha-1 around Bako and Didessa, 46/33 kg N/P ha-1 in Jimma area, 92/44 kg N/P ha-1 in Hawassa area and 69/30 kg N/P ha-1 in the Rift Valley were recommended for maize production [18]. Accordingly, the combined application of 90/15 kg N/P ha-1 fertilizers recommended for vertisols of around Aykel, Chilga district in North Gondar zone had improved maize grain yield (5.36 t ha-1) and yield components [19]. Similarly, [20] found that a combined application of NP gave a better grain yield of hybrid maize (BH-140) and improved P content of the soil. Higher grain yield of maize variety (Melkassa I), 3,868 and 5,069 kg ha-1 in Babile and Dire Dawa area were obtained with the combined application of 64/20 kg NP ha-1 [21]. The application of 69-20-75 kg N-P-K ha-1 for maize gave significantly higher yields compared to another recommended NP at Areka [22]. The minimum (4,687 kg ha-1) and maximum (4,905 kg ha-1) maize yield at Dangla in 2009 cropping season were obtained from control and 100 kg K2 O ha-1, respectively [23]. Similarly, at Mota, [23] found that the minimum (2,951 kg ha-1) and maximum (3,929 kg ha-1) yield of maize in the 2008 cropping season were recorded from the control and application of 100 kg K2 O ha-1, respectively. The mean grain yield of maize at both locations responded non-significantly to the applied K rates [23].

Maize yield responses to green manure: A field experiment was designed by Bako Agricultural Research Center (BARC) in three location to evaluate the possibility of replacing N-fertilizer and long-term fallow system with Dolichos lablab green manure for maize under the farmers’ field in three locations. The statistical analysis showed that there were significant (P<0.05) variations among the treatments on maize grain yield at all sites; however, the lowest grain yield was recorded at Shoboka (Table 1). The results revealed that green manuring provided comparable grain yield to that of the recommended NP fertilizers on marginal soil fertility status like BRC and Walda. Similarly, green manure of sole legumes could substitute for more than 70 kg urea N ha-1 at Jimma. Moreover, the application of Sesbania sesban’s biomass and dry FYM above 5 t ha-1 gave comparable or greater mean maize yield of up to 69 kg N ha-1 from urea fertilizer [24].

Farmyard manure and NP: Field observation and on-farm experiments conducted recently in Yabello district of the Borana, southern Ethiopia showed that maize responded positively to farmyard manure application. All treatments recorded significantly higher grain and stover yield of maize than did the control treatment that received no nutrient inputs (Table 2). The highest grain and stover yields were achieved where micro-doses of manure were combined with micro-fertilizer, followed by the recommended dose of fertilizers. Application of 70 g (corresponding to 3.71 tons per ha) of manure, combined with a small quantity (0.5 g per pocket) of fertilizer, improved maize grain yield by 77% compared to nonuse of inputs [25]. Additionally, manure applied alone yielded 51% of grain compared to the control (Table 2). Despite variation between treatments, the observed significant yield improvements compared to the usual non-use of manure shows considerable scope for increasing yields of these marginal lands by using manure. As long-term research strategy on locally available sources of organic fertilizers, a strategy was designed on a continuous basis for replenishing the degraded physic-chemical properties of soils to make sustainable maize production in Bako areas and similar locations. Accordingly, a study carried out on combined uses of NP and FYM at five on farms sites indicated that integrated application is better than application either NP or FYM alone (Table 3). While previous studies at the same location revealed that FYM has to be applied every three years at the rate of 16 t ha-1 supplemented by NP fertilizer annually at the rate of 20-46 N-P2O5 kg ha-1 (Table 3) for sustainable maize production around Bako and similar areas [26]. The sole application of FYM at the rates of 4-12 t ha-1 is also encouraging for resource poor farmers on relatively fertile soils [27].

Conclusion

Soil fertility decline that includes nutrient depletion, nutrient mining, acidification, the loss of Organic Matter (OM) and others, and poor cropping system have stayed to be the major factors causing hindrance to maize production in Ethiopia. In an attempt of counteracting and alleviating this problem in the country and to offer low input technology on soil fertilization, various research endeavours aiming at boosting the productivity of maize related to Soil property changes in a positive direction under use of different organic and inorganic fertilizer sources and improved cropping system had been made in different parts of Ethiopia by researchers and scholars from Agricultural Research Institutions found in the country. The findings of the reviewed research outputs of these efforts reveal that there is potential for increasing crop productivity through improved and available soil fertility management practices and cropping system.

The results of study conducted at Bako revealed that green manuring provided comparable grain yield to that of the recommended NP fertilizers on marginal soil fertility status. Similarly, green manure of sole legumes could substitute for more than 70 kg urea N ha-1 at Jimma. The analysis suggests that amending legume fallows and green manuring with mineral fertilizer may be important if high yield productivity must be sustained over several years, as yields normally fall as the post fallow cropping period lengthen. An experiment conducted in Bako concluded that use of 12 t ha−1 of FYM with 28/12 NP2O5 kg ha−1 saved up to 75% cost of commercial fertilizer. Another field experiment done in Western Oromiya, application of 150/50 kg ha−1 of Urea and DAP with 4 t FYM ha−1 was recommended for sustainable production of maize. The findings of similar study in Borena indicated that crop yield from the nutrient-poor soils of the region can be substantially enhanced by using manure, despite the traditional beliefs linking manure use to misfortune in the area. Use of five tons ha-1 of compost with 55/10 kg of N/P ha-1 is found economical for maize production in Bako Tibe district and other similar areas in western regions. Another trial proceeded at acidic nitosol of Southwestern Ethiopia concluded that application of 50% recommended NP and 50% compost gave the highest grain yield. A work done at Ebantu district, showed that integrated use of vermicompost at (2.5 t ha−1) and mineral P (20 kg ha−1) with lime (4 t ha−1) was recommended for reclaiming soil acidity and improve nutrients for maize. Hence, organic fertilizers can be applied with chemical fertilizers in organic carbon depleted arable soils to improve soil properties and crop productivity. Also, the combined use of organic and inorganic fertilizers has a positive synergy that can reduce the chemical fertilizer cost as well as mitigate the environmental hazardous effect.

Intercropping of maize with climbing bean within the same row at 10cm distance between maize and climbing bean with 150/50 kg ha-1 Urea /DAP and 4 t FYM ha-1 fertilizer combinations is recommended for sustainable production of component crops at Bako. Similarly, the buildup of soil fertility through establishing pigeon pea and its biomass retention evidently boost the productivity of the soil and even 100% reduction of chemical N fertilizer cost for maize production. Maize sown in rotation with nug and soybean at Bako and Jimma, respectively required one-half of the recommended fertilizer rates that crop rotations offset 50% of fertilizer cost. The production of maize following sole haricot bean with the recommended fertilizer rate gave higher mean grain yield and is recommended for sustainable production of maize in Bako area. Therefore, potential grain legumes and forage and fodder legumes should better be intercropped and utilized in rotation with maize to enhance soil fertility and boost grain yield at low cost for maize based farming system in Ethiopia.

Indexing List of Iris Publishers: https://medium.com/@irispublishers/what-is-the-indexing-list-of-iris-publishers-4ace353e4eee

Iris publishers google scholar citations: https://scholar.google.co.in/scholar?hl=en&as_sdt=0%2C5&q=irispublishers&btnG=

Search This Blog

Iris Publishers Agriculture Soil Science