Value Cost Ratio Research Articles

Maize (Zea mays L.) Response to Secondary and Micronutrients for Profitable N, P and K Fertilizer Use in Poorly Responsive Soils

Deficiencies of secondary and micronutrients (SMNs) are major causes of low maize yields in poorly responsive soils. This phenomenon minimizes the agronomic efficiency of N, P and K fertilizers and consequently result in a dwindling economic benefit associated with their use. Therefore, 18 on-farm trials were conducted in western Kenya during two cropping seasons to assess maize response to three NPK amendments; (i) N, P, K, Ca, Zn and Cu (inorganic and organic); (ii) N, P, K, Ca, Zn and Cu (inorganic) and (iii) N, P K, Zn and Cu (inorganic) and evaluate the profitability of their use compared to additions of only N, P and K fertilizers. In this set of experiments, maize response to any amendment refers to a yield increase of ≥2 t ha−1 above control and could be categorized in three clusters. Cluster 1, comprising of nine sites, maize responded to all amendments. Cluster 2, holding six sites, maize responded only to one amendment, N, P, K, Ca, Zn and Cu (inorganic). In this cluster, (2), emerging S, Mg and Cu deficiencies may still limit maize production. Cluster 3; consisting of three sites, maize responded poorly to all amendments due to relatively high soil fertility (≥17 mg P kg−1). Profitability of using NPK amendments is limited to Cluster 1 and 2 and the largest Value Cost Ratio (VCR) of 3.1 is attainable only when soil available P is below 4.72 mg kg−1. These variable responses indicate the need for developing site-specific fertilizer recommendations for improved maize production and profitability of fertilizer use in poorly responsive soils.

Reducing spatial variability of soybean response to rhizobia inoculants in farms of variable soil fertility in Siaya County of western Kenya

Soybean grain yields in sub-Saharan Africa have remained at approximately 50% below those attained in South America despite numerous efforts. A study was conducted in Siaya County (western Kenya) involving 107 farms with soils of different fertility status. The main objective was to test combinations of two inoculants (Legumefix and Biofix) and nutrient sources (Minjingu and Sympal) to raise soybean grain yields. Inoculation used Legumefix or Biofix with and without Minjingu or Sympal in a factorial design. There was soil acidity and a widespread deficiency of potassium, nitrogen, and phosphorus. Inoculation and nutrient source led to increases in nodulation and nodule occupancy. For grain yields the response varied from nil in some sites to high increases in others. Highest grain yields (3000–4000 kg ha−1) were obtained with Legumefix + Sympal (12% of the farmers testing it). The formulation of the nutrient source was important to meet other nutrient deficiencies in most of the soils. Farmers using Legumefix + Sympal require yield increases of 35% for profitability (Value cost ratio of 3) while farmers using Minjingu + inoculant require a yield increase of at least 68%. Inoculants used alone were most profitable but this is advisable only when farmers are too resource constrained to afford fertilizer. For sustainable yields Legumefix + Sympal or Biofix + Sympal were recommended.

ANALISIS TINGKAT KEUNTUNGAN USAHA PENGGEMUKAN SAPI POTONG RAKYAT DI KABUPATEN WONOGIRI

Beef cattle breeding business in Wonogiri District is dominated by small scale in which capital and profits too low. The size of the profits derived from the balance of the sale value of production and production costs that is issued by the breeder. The maximum profit would be achieved if all factors of production have been allocated in an optimal and efficient use, both technically and economically efficient manner. Objective analysis profit function is to describe the situation now, the circumstances in the future or planning and action of a business related to the rate of business profit and net income scale beef cattle farms of the people.The results showed that total revenue (TR) of beef cattle breeding business people have an average of Rp.89.360.625.00 per farmer per one period of fattening cattle, while the total cost (TC) on average Rp.85.119.873.00 each farmers per one period of fattening cattle. So that the magnitude of the rate of profit(π) obtained by each farmer in one period of fattening cattle for Rp.4.240.752.00 and the R / C ratio of 1:05. The results of the analysis showed that the profit rate of beef cattle breeding business in Wonogiri Regency financially advantageous (value profit π> 0 and the return value cost ratio of R / C> 1). Results of regression equation analysis function simultaneously benefit breeders show concentrate feed costs, labor costs and costs of cows significant ((P <0.05)) on the level of business profit beef cattle farms in Wonogiri. Based on the calculation of the value of R2 adjusted Rvalues obtained2 83.2% showed variable variation concentrate feed and forage costs, drug costs, labor costs, fees and charges cage feeder cattle can be explained by either a variable rate of the business profits of beef cattle breeders. The remaining 16.8% operating income level variable cattle ranchers explained by variations in other variables outside the model. Partially variable concentrate feed costs, labor costs and the cost of feeder cattle significantly (P <0.05) to the level of business profit breeding beef cattle people. As for the cost of forage ariable drug costs are not significant (P> 0.5) on the level of beef cattle breeding business benefit of the people. Keywords: Function Gain, Beef Cattle, Wonogiri

Combining hill-placed manure and mineral fertilizer enhances maize productivity and profitability in northern Benin

Throughout much of Sub-Saharan Africa (SSA), maize production is characterized by low productivity due to the scarce availability and use of external inputs and recurrent droughts exacerbated by climate variability. Within the integrated soil fertility management (ISFM) framework, there is thus a need for optimizing the application of fertilizers and manure to better use the limited nutrient resources and increase crop yield and farmer income. An on-station experiment was conducted in Northern Benin over a 4-year period to evaluate the effect of hill placement of mineral fertilizer and manure on maize yields and soil chemical properties. The treatments consisted in the combination of three rates of manure (0 (NM), 3 (3M) and 6 (6M) Mg ha−1) and three levels of fertilizer (0% (NF), 50% (50F) and 100% (100F) of the rate recommended by extension (76 kg N + 13.1 kg P + 24.9 K ha−1)). On average across the fertilizer rates, hill-placement of manure significantly improved soil organic carbon content, available P and exchangeable K after 4 years by up to 124, 166 and 77%, respectively, compared to the initial values. As a result of the nutrient inputs and improved soil properties, yields increased steadily over time for all manure and fertilizer combinations. Value-cost ratios and benefit–cost ratios were >2 and generally as good or even better for treatments involving 50F compared to NF or 100F. Although applying half the recommended rate of fertilizer without manure as currently done by many farmers appears to make economic sense, this practice is unlikely to be sustainable in the long term. Substituting 50F for 3M or complementing 50F with 3M are two possible strategies that are compatible with the precepts of ISFM and provide returns on investment at least as good as the current practice. However, this will require greater manure production, made possible in part by the increased stover yields, and access to means of transportation to deliver the manure to the fields.

Profitability of diammonium phosphate use in bush and climbing bean-maize rotations in smallholder farms of Central Burundi

Soil fertility decline is a major constraint to bean (Phaseolus vulgaris L.) and maize (Zea mays) production in the Central Highlands of Burundi. Nutrient sources, specifically fertilizers, are paramount to increasing the production in the regions. Hence, improving fertilizer use efficiency is considered as a key factor towards sustainable intensification. The use of grain legumes with low harvest indices, such as climbing beans, are assumed to improve soil fertility and fertilizer use efficiency. This study compares the rotational effects of bush and climbing bean varieties on maize and evaluates the profitability of diammonium phosphate (DAP, 18–46-0) fertilizer in the bean-maize rotations in 59 smallholder farms of Mutaho district, Gitega Province in Central Burundi. The application of DAP fertilizer significantly increased the grain yields by 14% and 21% for bush and climbing beans, respectively (P<0.001). Positive effects of bean varieties were large for about 80% of the farmers. Climbing beans in general yielded more than bush beans for about two thirds of the farmers and fertilizer effects were positive. In the bean-maize rotations, the fertilizer induced on average a yield increase of 8% and 22% for maize following bush and climbing beans, respectively. Maize grain yields were significantly (P<0.001) higher following climbing beans than following bush beans. The value cost ratio (VCR) more than doubled compared with the common practice (bush bean-maize rotation). Variation was substantial, and for approximately 67% of the farmers, DAP application was profitable (VCR>2 $ $−1) in a climbing bean-maize rotation while 45% of the farmers in a bush bean-maize rotation. Regression tree analysis showed that targeting fertilizer use to soils with higher C and clay content, and ensuring timely planting are the predominant factors to ensure fertilizer response and profitable returns. This study confirms the need for integrated soil fertility management (ISFM), and that a combination of judicious fertilizer use, an improved grain legume (climbing bean) and adjustment to local conditions (targeting to responsive soils) maximizes economic returns of legume-cereal rotation systems.

Occurrence of poorly responsive soils in western Kenya and associated nutrient imbalances in maize (Zea mays L.)

A poor response to fertilizer application is one of the persisting constraints preventing closure of the maize yield gaps in Sub-Saharan Africa (SSA). It is speculated that nutrient imbalances derived from deficient and/or excessive concentrations could be one of the causes of this limited response of maize to fertilizer. This is however not confirmed and the extent of such poor response is ill-documented. To investigate this, we conducted 44 on-farm trials with a two treatment structure (with and without NPK fertilizer) in two subsequent seasons, the 2014 long rains (LR) and short rains (SR) distributed across two sites: Bungoma-Southwest and Busia-North in western Kenya. As a discriminating criterion between responsive and poorly responsive soils, we used a Value Cost Ratio (VCR) of 2 of NPK fertilizer use. Nutrient sufficiency ranges were developed using compositional nutrient diagnosis (CND method) and then used to identify both deficient and/or excessive nutrient concentrations occurring in maize grown in the poorly responsive soils.Results show that 48% of all fields from both sites could be classified as ‘poorly responsive’, with small VCR values ranging between 0.1 and 1.99. Nutrient deficiencies were more prevalent than situations of excessive concentrations in such fields. N-deficiency was the most common in the unfertilized (control) plots occurring in between 80 and 89% of the poorly responsive plots. Zn-deficiency became apparent in the fertilized plots and was observed at similar frequencies in this treatment. The next most widespread nutrient deficiencies in poorly responsive soils were those of P and Cu affecting between 70 and 79% of both control and fertilized plots. K and Mg deficiencies were rare in both treatments. This study indicates that the occurrence of poorly responsive soils in Bungoma-southwest and Busia-North is likely related to micronutrient deficiencies. These findings necessitate further investigation on the bioavailability of these micronutrients nutrients in such soils and a validation trial to evaluate the extent of crop responses.

Maize yield response, nitrogen use efficiency and financial returns to fertilizer on smallholder farms in southern Africa

Maize is considered as “life” in southern Africa because it is the staple food crop and the main component of food aid interventions. However, its productivity is very low, partly because of the limited use of external inputs. Although maize response to fertilizer has been the focus for many years of studies on research stations, information is scanty on the level of crop response and profitability on smallholder farms in most parts of southern Africa. Therefore, the objective of the present analysis was to determine yield responses, nitrogen use efficiency and returns to investment in fertilizer in the unimodal rainfall region of southern Africa. This analysis compared yield responses to various rates of nitrogen (N) fertilizer with maize grown without external inputs (absolute control) on a total of 940 demonstration sites in 47 districts across Malawi, Mozambique, Zambia and the southern highlands of Tanzania. Across the sites, average yields were 1.6 t ha−1 in the control, 2.8 t ha−1 with ≤50% of the recommended N rate and 4 t ha−1 where 100% or more of the recommended N rate was applied. Except in Zambia, agronomic efficiency and partial factor productivity of N were higher with 50% of the recommended N rate compared to 100% of the recommended N rate. Net present values (NPV) were also positive in over 50% of the cases, indicating that investments in N fertilizer will generate profits over time. In contrast, for maize grown without N fertilizer, NPVs were negative in over 68% of the cases across the four countries. The value-cost ratio was >2 with the various N rates at the aggregate level, but it was <2 on sites in Mozambique and Zambia. We conclude that growing maize without N inputs results in loss of land productivity and profitability while application of 50% or more of the recommended N fertilizer ensures substantial increases in yields and profitability.

Ground cover management and farmyard manure effects on soil nitrogen dynamics, productivity and economics of organically grown lettuce (Lactuca sativa L. subsp. secalina)

Ground cover management and farmyard manure (FYM) management have important roles in organic lettuce production. However, there is not enough information about their combined effects. In order to assess the effects of individual and combined ground cover and FYM management on soil mineral N (NH4-N and NO3-N) dynamics, lettuce yield and economics in organic farming, a two-year field experiment was conducted on a certified organic farm in Kisač (Vojvodina, Serbia). The experiment had a two-factorial split-plot completely randomized block design. FYM was applied on the half of the experimental field as a whole-plot factor, while ground cover management included the following four treatments: (I) control, without ground cover management (Ø); (II) hoeing (H); (III) agrotextile cover; (IV) straw mulch (SM), which were applied on split plots. The applied SM and AT increased soil moisture by 12.83 and 3.73%, respectively, compared to the control treatment. FYM increased soil mineral N concentration, the lettuce fresh matter (FM) yield and nitrate concentration in lettuce. However, nitrate concentration in lettuce in all treatments was below the limit required by the European Commission (EC) (2001). The highest lettuce yield was obtained by AT (39 122 kg), followed by SM (33 925 kg), and it was higher with FYM application by 16.85%. Hoeing did not positively affect the yield, probably due to its negative effect on soil moisture. Additional profit was higher with FYM, showing the following decreasing order: AT>H>SM>Ø. However, value/cost ratio (VCR) was in the order Ø>H>SM>AT on FYM fertilized plots. FYM application led to higher lettuce yield and higher profit and VCR. In case a farm does not have FYM, SM is the best alternative due to its positive effect on the yield and low investment costs.

Moving in the right direction? The role of price subsidies in fertilizer use and maize productivity in Ghana

Despite major maize programs in the last two decades and costly investments in a price subsidy program in Ghana, maize productivity remains very low. Utilizing cross-sectional data on 645 maize plots in Ghana, this paper provides empirical evidence on the responsiveness of maize yield to fertilizer application, profitability of fertilizer use, and how the economics of fertilizer use have changed with the subsidy program. There was a statistically significant maize yield response to increased fertilizer application (i.e. 1-kg of nitrogen leads to a yield increase of 22–26 kg per hectare), higher than those estimated in other countries in Africa. Value-cost ratio shows that maize production with fertilizer is profitable both at market and subsidized prices in different locations and with different farming practices, even after incorporating risk into the estimation and analysis. However, despite subsidized prices and profitable fertilizer use, the actual application rate (at 44 kg/ha of nitrogen on average) is much lower than research institute’s and government recommendation and far off the computed economically “optimal” levels (at 225 kg/ha of nitrogen; where the fertilizer price intersects the value of marginal physical product derived from the yield response model). Results suggest that fertilizer prices do not seem to be the binding constraint in greater fertilizer application and productivity increases in maize; other factors appear to be major bottlenecks to greater fertilizer application and productivity increases including accessibility to modern varieties, mechanization, and hired labor. This result shows the limits to fertilizer subsidy as the focus strategy and suggests a more integrated and holistic approach to encourage greater fertilizer application, productivity and income among maize farmers in Ghana.

Optimizing Nutrient Use Efficiency and Returns from Soybean Production under Smallholders in Three Agro-Ecologies of Malawi

Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer rates on rain use efficiency (RUE), harvest index, agronomic use efficiency of phosphorous (AEP) and potassium (AEK), and value cost ratio (VCR) were evaluated. The applied diagnostic PK fertilizer rates significantly improved soybean grain yields, harvest index, rainwater use efficiency, AEP, AEK and returns to fertilizer use expressed as value cost ratio (VCR). However, the results differed significantly (P < 0.01) among the three agro-ecological zones. The VCR values indicated that the most economical and profitable fertilizer rate was 7.5 kg/ha P in Salima, Dedza and Lilongwe. The lowest economical and profitable NP fertilizer rate was 22.5 kg/ha P plus 20 kg/ha K for Dedza and Lilongwe and 15 kg/ha P plus 30 kg/ha K for Salima District. All the VCR values obtained from applying different PK fertilizer nutrient rates were above two implying that all the applied fertilizer rates had a good value of returns to adequately cover against any risks associated with using fertilizers at small-scale under smallholder farms with inadequate financial resources. The results also presented different available NP fertilizer application rate options for maximizing profits for the financially constrained smallholder farmers.

Returns to fertiliser use: Does it pay enough? Some new evidence from Sub-Saharan Africa

The low level of modern inputs adoption by African farmers is considered to be a major impediment to food security and poverty reduction in Sub-Saharan Africa. The government of Burkina Faso, following the example of a number of other countries in the region, launched a subsidy programme in 2008 to encourage farmers’ uptake of chemical fertilisers and foster cereal production. This article explores the importance of fertiliser profitability in explaining the relative, apparent low use of chemical fertilisers by farmers in Burkina Faso. Using large-scale plot data, we estimate maize yield response to nitrogen to be 19 kg/ha on average and to vary with soil characteristics. Profitability, which we measure through the calculation of a marginal value cost ratio, is estimated at 1.4 on those plots which received fertilisers, with significant variations across regions. For those plots on which fertilisers were not applied, we predict that fertilisers should have been profitable in most cases under the current level of subsidised fertiliser prices. These findings suggest that the low uptake of chemical fertilisers might have been driven by factors other than profitability, including insufficient supply of subsidised fertilisers to farmers in need. Our results also call for increasing the availability of credit to farmers in order to encourage adoption of chemical fertilisers. Finally, our results also show that not taking into account the endogeneity of nitrogen use in the yield equation may produce biased estimates of the maize yield response to nitrogen.

PARTICIPATORY RESEARCH TO CLOSE THE SOYBEAN YIELD GAP ON SMALLHOLDER FARMS IN MALAWI

SUMMARYSoybean yields on smallholder farmers’ fields in Malawi are constrained by poor soil fertility, limited application of external inputs and poor crop husbandry. We tested crop management practices through on-farm experimentation and participatory technology evaluation. Two agronomic soybean trials were established in 2009 and 2010 in three contrasting agro-ecologies resulting in 72 replications per trial. Treatments in the first trial included several combinations of inoculation withBradyrhizobium japonicum, inorganic fertiliser application and compost manure. In the second trial, farmers tested an improved variety, optimal weeding regime, increased plant population and chemical pest and disease control. A combination of inoculation, inorganic fertiliser (10 N, 8 P, 20 K in kg ha−1), and 6 t ha−1compost manure increased yields from 0.86 t ha−1under farmers’ practice to 1.56 t ha−1and resulted in average profits of US$222 ha−1. Increased plant populations and biocide spraying also resulted in substantial yield increases. Inoculation and increased plant population resulted in an average value to cost ratio (VCR) &gt; 2. Low investment costs make inoculants, compost manure and increased plant populations interesting options, whereas adoption of inorganic fertiliser application in soybean may be limited due to high costs and low VCR. The farmers ranked eight technologies in descending order of preference as: (i) early planting, (ii) plant population, (iii) variety choice, (iv) compost manure, (v) weeding, (vi) inoculant, (vii) fertiliser and (viii) spraying. Our participatory research approach demonstrated that there is a wide range of technologies with different levels of human and financial investment costs that smallholder farmers can adopt to enhance their soybean yields and profits.

Improving air pollution control policy in China—A perspective based on cost–benefit analysis

To mitigate serious air pollution, the State Council of China promulgated the Air Pollution Prevention and Control Action Plan in 2013. To verify the feasibility and validity of industrial energy-saving and emission-reduction policies in the action plan, we conducted a cost–benefit analysis of implementing these policies in 31 provinces for the period of 2013 to 2017. We also completed a scenario analysis in this study to assess the cost-effectiveness of different measures within the energy-saving and the emission-reduction policies individually. The data were derived from field surveys, statistical yearbooks, government documents, and published literatures. The results show that total cost and total benefit are 118.39 and 748.15 billion Yuan, respectively, and the estimated benefit–cost ratio is 6.32 in the S3 scenario. For all the scenarios, these policies are cost-effective and the eastern region has higher satisfactory values. Furthermore, the end-of-pipe scenario has greater emission reduction potential than energy-saving scenario. We also found that gross domestic product and population are significantly correlated with the benefit–cost ratio value through the regression analysis of selected possible influencing factors. The sensitivity analysis demonstrates that benefit–cost ratio value is more sensitive to unit emission-reduction cost, unit subsidy, growth rate of gross domestic product, and discount rate among all the parameters. Compared with other provinces, the benefit–cost ratios of Beijing and Tianjin are more sensitive to changes of unit subsidy than unit emission-reduction cost. These findings may have significant implications for improving China's air pollution prevention policy.

The Response of Sorghum, Groundnut, Sesame, and Cowpea to Seed Priming and Fertilizer Micro-Dosing in South Kordofan State, Sudan

This study was undertaken with the objective of evaluating micro-dosing of mineral fertilizer combined with seed priming in sorghum, groundnut, sesame, and cowpea. On-station and on-farm trials were conducted for two consecutive seasons (2009/2010 and 2010/2011) at Al-Tukma village (12°00′57.60′′ N and 29°46′12.15′′ E) in South Kordofan State, 15 km southeast of Dilling city. Heavy cracking clay soil is the dominant soil type in the region with low fertility. The experiments for each crop consisted of two priming levels (primed seeds vs. non-primed) and four micro-doses of NPK mineral fertilizer (0, 0.3, 0.6 and 0.9 g per planting pocket or hole). On-farm trials in 15 fields consisted of control, seed priming, and seed priming + micro fertilizer (0.3 g/planting hole). Data collected included plant vigor, stand count, plant height, grain and straw yield, seed weight, and other relevant agronomic traits. This study shows that it is possible to increase productivity of sorghum, sesame, groundnut, and cowpea in the semi-arid cracking clay of South Kordofan State at a low cost and with a moderate risk for farmers through seed priming and micro-dosing of fertilizers. Seed priming combined with micro-dosing NPK mineral fertilizer of 0.9 g was the best treatment for plant establishment, seedling vigor, grain yield, and hay yield in sorghum and groundnut, whereas the combination of seed priming and 0.3 g micro-doing of fertilizer was the best in sesame. Seed priming and micro-dosing of fertilizer of 0.6 g was the best combination for cowpea. On-farm trial results indicated that priming alone and priming combined with fertilizer application significantly increased the yields of sorghum, groundnut, and cowpea over the control (P = 0.01). Of the crops tested, groundnut responded most favorably to micro-dosing and seed priming, with a value to cost ratio (VCR) of 26.6, while the highest VCR for sorghum, sesame, and cowpea was 12.5, 8.0 and 4.4, respectively. For the best productivity and profitability, we recommend using seed priming in combination with the micro-dosing of 0.9 g/hole of 15:15:15 NPK fertilizer for sorghum and groundnut, of 0.3 g/hole for sesame, and of 0.6 g/hole for cowpea grown in the semiarid South Kordofan State of Sudan.

Sensitivity analysis of energy inputs and cost assessment for almond production in Iran

The objectives of this study were to investigate the relationships between energy inputs and yield, and to perform cost analysis for almond production. Data were collected by administering questionnaire in face‐to‐face interviews from procedures. The results showed that total energy input was 59,542.61 MJ ha−1 and the output was 25,190.13 MJ ha−1. The most important energy consuming inputs were electricity and chemical fertilizers with 55.98% and 17.72% of total energy input, respectively. The energy use efficiency and energy cost ratio values were estimated to be 0.42 and 0.19, respectively. The econometric model was developed using Cobb‐Douglas production function and the results revealed that human labor, machinery, chemical fertilizer, and farmyard manure energy inputs contributed significantly to yield. The results of sensitivity analysis of energy inputs showed the high impact of chemical fertilizers, and farmyard manure inputs on the yield. Economic analysis showed that the total production cost, total gross value, and net return of almond production were 5344.48 $ ha−1, 27,241.29 $ ha−1, and 21,896.81 $ ha−1, respectively. Also, productivity and the benefit to cost ratio were obtained to be 0.16 kg $−1 and 5.10, respectively. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 582–588, 2016

Maize response to macronutrients and potential for profitability in sub-Saharan Africa

Sub-Saharan Africa (SSA) is plagued by low productivity and little research is available on the attainable responses and profitability to applied nutrients under variable environments. The objective of this study was to determine the attainable maize grain response to and potential of profitability of N, P and K application in SSA using boundary line approaches. Data from experiments conducted in SSA under AfSIS project (2009–2012) and from FAO trials database (1969–1996) in 15 countries and constituting over 375 different experimental locations and 6600 data points are used. Both response to fertilizer and value cost ratio (VCR) are highly variable and no more than 61 % cases for N, 43 % for P and 25 % for K attain VCR of 2 or more. Also, based on the recent AfSIS data, VCR exceeds 1 in just 67 % (N), 57 % (P) and 40 % (K) of the cases, even when best management practices are applied on a research farm, and interest rates are zero. Chances for profitability are highest when soil organic carbon is 1–2 % and control maize grain yield is 1–3 t ha−1 but also depends on relatively static soil properties (primarily texture and mineralogy) that are not under farmer control. We conclude that return on investment of macronutrient fertilizer is highly variable and can be substantially increased by helping farmers decide where to apply the fertilizers. Consequently, farmers need access to information on factors influencing economic returns of fertilizer use in order to make the right decisions.

Improving Rice Productivity and Profitability with a Single Fertilizer-Management Option over Two Cropping Seasons in the Senegal River Valley

One of the main factors limiting the yield and productivity of irrigated rice in the Sahel of West Africa is the high cost of fertilizers and inefficient use of nutrients in the cropping systems. A two-year experiment was conducted over four consecutive seasons at Ndiaye (16°11'N, 16°15'W) and Fanaye (16°32'N, 15°11'W) along the Senegal River Valley to investigate alternative fertilizer management options in the double cropping system of rice. Eight fertilizer management options (FMO) were compared to the recommended seasonal application of NPK fertilizer based on yield data, the value-cost ratio (V/C) and the sustainabily of the recommendation. Rice yields increased from 2.5 t/ha without fertilizer application to 8 t/ha under the nine FMOs, which produced similar yields each season at both sites. The V/Cs of the recommended NPK fertilizer (applied each season) varied from 2.3 to 3.7. The V/Cs of FMO that supplied NPK during the hot dry season (HDS) and N during the wet season (WS), or conversely (NPK-N) varied from 3.2 to 5.7. The V/Cs of NPK-NP varied from 2.4 to 4.3. The V/Cs of NPK-NK varied from 2.4 to 4.4. The highest V/Cs ratios (5.2 to 6.3) were obtained by FMOs that supplied NP during the HDS and N during the WS, or conversely. It is concluded that when soil P-Bray1 is above 7 mg P ha-1, FMOs that supply NPK fertilizer in one season and only N fertilizer in the following season could reduce the cost of fertilization by 26% and improve rice productivity for sustainable management of the double cropping system of rice in the Senegal River Valley.

SEQUENTIAL EFFECTS OF MINIMUM TILLAGE, SEED PRIMING, FERTILIZER MICRODOSING AND MULCHING IN MAIZE, SEMIARID CENTRAL RIFT VALLEY OF ETHIOPIA

SUMMARYIntensification of maize production is imperative to improve food security for the rising population in the central rift valley (CRV) of Ethiopia, whose livelihood is principally based on rainfed maize that operates under shrinking landholding and high seasonal rainfall variability. This study examined different levels of intensification options in maize production by sequentially introducing minimum tillage and seed priming, phosphorus (P) fertilizer microdosing, surface mulching and nitrogen (N) fertilizer microdosing. Field experiments were conducted with five treatments, steps or levels consisting of conventional tillage (farmers practice as a control); minimum tillage + seed priming, unfertilized (step 1); step 1 + microdosing 53 kg ha−1 P (step 2); step 2 + 4 ton ha−1 maize stover as surface mulch (step 3) and step 3 + 53 kg ha−1 N (step 4). These steps represented increasing levels of intensification. Except at the lowest level (step 1), agronomic and economic responses improved with increasing levels of inputs. Relative to the very high and increasing gross margin, production costs were low but slowly increased with increasing levels of inputs. Except at the lowest level, the value cost ratio was above 4 even at the highest levels of inputs, demonstrating that such kind of intensification can be achieved with low risk. Likewise, the fertilizer use efficiency was quite high even at the highest of levels of inputs signifying the efficiency of the pocket application of fertilizer through the microdosing method. The improvement in maize establishment and yield and the reduction in the days to maturity could contribute to make maize production more adaptive to the existing seasonal rainfall variability. Depending on the affordability to the external inputs and their feasibilities, the different technology packages in the intensification ladder may give different choices for the farmers to improve maize production in the CRV of Ethiopia.

Nitrogen Rates and Sources Affect Yield and Profitability of Maize in Pakistan

Nitrogen is one of the most important factors affecting maize yield and profitability. To investigate the impact of N fertilizer sources (urea, calcium ammonium nitrate [CAN] and ammonium sulfate [AS]) applied in various amounts (0, 50, 100, 150, and 200 kg N ha−1) on grain yield and profitability of maize genotypes, local cultivars (Azam and Jalal) versus hybrid (Pioneer‐3025) field experiments were done during summer 2008–09 (Year 1) and 2009–10 (Year 2). The N yielded 41 and 26% more grain than the check in Year 1 and Year 2, respectively. In both years, grain yield increased in response to the increase in N application. Application of CAN and AS resulted in more grain yield than urea in Year 1, while no differences in yield were observed in Year 2. The hybrid (P‐3025) yielded 30 and 24% more grain than the average of local cultivars in Years 1 and 2, respectively. In Year 1, the net returns (NR) of PKR16262 ha−1 (one US$ = 95 Pakistani Rupees) was obtained with CAN but value cost ratio (VCR) of 3.7 was noticed with urea; in Year 2, both NR (PKR14271 ha−1) and VCR (3.1) was greatest with urea. In both years, the greatest NR was obtained with 100 and 150 kg N ha−1. Application of urea at 150 and 200 kg N ha−1, CAN at 100 and 150 kg N ha−1, and AS at 50 and 100 kg N ha−1 was economical in terms of NR in both years.

English

Field studies were conducted over two years with the objectives to improve soil fertility and minimize the use of commercial fertilizer. It was comprised of three tillage practices included minimum (MT), conventional (CT) and deep (DT) and twelve nitrogen sources treatments including farm yard manure (FYM) (10 or 20 tons ha), soybean residue (SR) (10 tons ha) in sole and/or in conjugation with half of inorganic nitrogen (UN) as urea (60 or 120 kg ha), a control and sole full doses of inorganic N. Low soil fertility and yield was observed for deep tillage than minimum or conventional tillage. Minimum tillage improved soil fertility in term of mineral N as well crop productivity and uptake of N (11%) compared to DT. FYM (20 tones ha) and UN (60 kg ha) application improved soil fertility, crop productivity, and grain protein. Mixed application of FYM and urea increased total N uptake by plants and yield efficiency in term of harvest index was better for SR+UN treatment. Value cost ratio was higher for sole FYM, whereas relative increase in income was higher for FYM+UN. Thus using a mixture of FYM and UN under minimum tillage might be an optimum agronomic practice for improved productivity, soil fertility and economical disposition of waste material. Further studies are suggested to quantify the form of N uptake by plants for better and sustainable N management practices in cereal base (wheat-maize) cropping system. © 2015 Friends Science Publishers