The spatial price predictions–“price maps”–that are generated by our approach can be used to improve empirical research on technology use (by more accurately approximating local input and output prices faced by farmers), as well as incorporated into targeting and planning frameworks for agricultural investments (e.g. Is the Subject Area "Fertilizers" applicable to this article? All the prices are non-subsidized. For the regional models we also used median country level price as a predictor variable. The TPS model was implemented using the ‘Tps’ function in the R-package ‘fields’ [43] with only longitude and latitude as predictor variables. The three countries with the most expensive urea are landlocked (Burundi: 1.51, Uganda: 1.49 and Burkina Faso: 1.49 USD kg-1) (Table 2). e0227764. Our study uncovers considerable spatial variation in fertilizer prices within African countries. A wide variety of npk fertilizer and prices options are available to you, such as compound fertilizer, organic fertilizer. The regression models for all locations showed a strong association between the price of urea and that of the other products. No, Is the Subject Area "Tanzania" applicable to this article? Last. https://doi.org/10.1371/journal.pone.0227764.g005. Kynoch has been a leader in the manufacturing of fertilizer in South Africa with approximately 80,000m 2 of raw materials handling capacity. While we were able to remove outliers, we had no way of correcting error for prices that were within a reasonable range of values. Fertilizers Yara fertilisers, solid or liquid, supply all crop nutrients including nitrogen, sulphur, phosphate, potassium and a full range of micronutrients Crop information pooled observations from multiple countries within a region), we predicted prices for the whole region with a single model. Yes 0.93. The countries with the most expensive NPK were Burkina Faso, Burundi, Malawi, Mali, Mozambique, and Uganda (between 1.57 to 1.63 USD kg-1) (S1 Table). We thank Drs. Fertilizers come in different compounds and blends. Fertilizer consumption is the key to Africa's food security. Vegetables, Flowers, Fruit, Base Ground and Top Dressing. In several countries, for example, Côte d’Ivoire, Ethiopia, Kenya, Mali, Uganda, and Zambia, prices were lower closer to the capital and or other main markets. Writing – review & editing. Except for Senegal, these countries are neighbors and use a common currency (West African CFA franc). within or near the village, within or near the nearest urban center, outside the district or region). In all the towns, subsidized prices were lower than non-subsidized prices. Discover a faster, simpler path to publishing in a high-quality journal. We compiled 7823 observations for 878 locations in seventeen countries: Benin, Burundi, Burkina Faso, Côte d’Ivoire, Ghana, Kenya, Mali, Malawi, Mozambique, Niger, Nigeria, Rwanda, Senegal, Togo, Tanzania, Uganda, and Zambia from 2010–2018. In addition, for Nigeria and Malawi LSMS reported transportation used by farmers to get to the market and transportation cost. Although the Africa fertilizer model performed slightly better than the LSMS model (ER: 0.26 vs 0.21); LSMS had much more data, and a better geographic coverage. The coefficient of variation (CV) in prices was above 25% for Ghana, Kenya, Malawi, Nigeria, Senegal, Tanzania, Uganda, and Zambia. 3. For countries with two data sources (Africa Fertilizer and LSMS), the prediction of the best-performing model is shown. Data Availability: Data are available in: (https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/E0EHLO). https://doi.org/10.1371/journal.pone.0227764.s002, https://doi.org/10.1371/journal.pone.0227764.s003, https://doi.org/10.1371/journal.pone.0227764.s004, https://doi.org/10.1371/journal.pone.0227764.s005, https://doi.org/10.1371/journal.pone.0227764.s006, https://doi.org/10.1371/journal.pone.0227764.s007. All predictor variables were organized as spatial raster data sets with a 5 arc-minute (about 9 × 9 km) spatial resolution. 9.8%. The range in the predicted relative prices within the countries was between 0.59 and 1.40 (Figs 5 and 6). In Nigeria, for transportation 52% of the farmers used a motorcycle, 36% used a truck/bus/minibus, 5% a commercial bicycle, and the rest used either a wheelbarrow, own bicycle, animal cart, on foot, or a boat. The predictions from a single regional model are similar to that of the combined country-based models, but with reduced spatial variation within countries (Figs 9 and 10). A downside of using such algorithmic methods is that there is no direct way to estimate uncertainty. For more information about PLOS Subject Areas, click It is challenging to evaluate these hypotheses, because each one of them may be true in some location or under certain conditions, and because the location specific data needed for analysis is not readily available. For Nigeria and Malawi, LSMS reported type of transportation and transportation costs farmers paid in order to obtain the fertilizer from the market. DAP [(NH4)2HPO4] is the world’s most widely used phosphorous fertilizer and is also a source of N. It contains 18% N and 20% P. To allow for comparison of prices between years and countries, we converted prices from national currency to inflation-adjusted purchasing power parity United States dollars (USD) by dividing them by the consumer price index (CPI) times the purchasing power parity (PPP) dollar value for each year according to the World Bank [3]. Regional models are attractive as they could be used to predict price variation in countries for which we have limited local market price data, but we did not investigate that here. Subsidized prices were much lower than non-subsidized prices in Malawi (9%) and Zambia (18% of the non-subsidized price). The South African fertilizer industry manufactures a broad range of fertilizer products as compounds or mixtures which contain two or more of the Primary Macro plant nutrients Nitrogen (N), Phosphorus (P) and Potassium (K) which are broadly referred to as NPK products. 1.70. The LSMS would appear to be an attractive data source by virtue of the large number of records of prices paid by farmers. To avoid an imbalance in the model evaluation, we used a sub-sample of the test data for these countries, with the sample size equal to the mean number of observations for the non-LSMS countries in the region. Urea [CO(NH2)2] is the world’s most widely used form of inorganic nitrogen fertilizer. Suppliers with verified business licenses. Prices are for 25 kg or 50 kg bags and expressed in the national currency. We … We provide clients across the country (Gauteng, North West, Free State, Eastern Cape, Western Cape, Northern Cape, Limpopo, KwaZulu-Natal and Mpumalanga) with specially developed fertilizer products that meet their needs. NPK fertilizer 8-24-24. We retrieved 12659 observations of farmer-reported urea prices from LSMS and retained 10528 observations. Stay updated to what's new and popular on the market. A variable is included if the % increase in Mean Square Error was more than 10% in a country-level Random Forest model. In Tanzania, prices were relatively low in the south and coastal region and higher at the northwest. Get the liquid fertilizers you need from the leading fertilizer supplier in South Africa. In 10 countries, predictions were at least 25% better than a null-model that assumes no spatial variation. The lowest number of observations was for Benin (41), Niger (27), and Togo (26) (Table 2). PLoS ONE 15(1): For Rwanda, the spatial models performed worse than the Null model and the range in the relative prices was very low (0.99–1), so we assume no (systematic) variation in urea prices in these countries; and for that reason we did not include maps for Rwanda. https://doi.org/10.1371/journal.pone.0227764.g008. For example, a purchase of 2 kg of urea for 79 USD is unlikely, whereas dividing that price by 100 kg (for two bags of 50 kg) yields a plausible price of 0.79 USD kg-1. No, Is the Subject Area "Africa" applicable to this article? At BulkFertilizer.co.za we have been selling plaas kunsmis / fertilizer for the wholesale market since 2009, supplying clients all over Southern Africa such as Namibia, Botswana, Zimbabwe and Mozambique.. (Along with phosphorous and potassium, nitrogen is one of the three components of miner… However, in Ghana and Benin the prices were lower in the north, further away from the capitals and main ports. To better understand patterns of, and opportunities for, fertilizer use, location specific fertilizer price data may be relevant. [NH4NO3 + CaCO3 * MgCO3]) but in general it contains 8% of Ca and 21–27% of N as [NO3-] and [NH4+]. Random Forest models tend to predict very well within the range of the observed values, but the predictions may show sudden breaks, and can be poor in extrapolating. Email * Comment or Message * Submit -> Goldfield Music animations: Safari Animation 2020 (Dancing Animals) - Funny Christmas Animation 2020 - Trance Music Animation 2020 - NEW Stronger Song 2020-> Goldfield Music videos: African Protests 2020 (Stronger Song) - Africa … We used that information to calculate the price of fertilizer per kg. The average national price was lowest in Ghana (0.80 USD kg-1), Kenya (0.97 USD kg-1), and Nigeria (0.99 USD kg-1). ER: Relative mean square error, calculated as: 1-(EI / E0). However, the spatial prediction of the combined model could be more realistic mostly in the south-east where no data from Africa Fertilizer was reported (Fig 8). There are 132 npk fertilizer suppliers, mainly located in Africa. In Rwanda and Malawi, the fertilizer subsidy program may also be lowering the variation and complicating the pattern of spatial price variation. Comparison of fertilizer and crop prices 29 List of tables 1. Visualization, International Food Policy Research Institute (IFPRI), Washington, DC, United States of America, Roles These results suggest that there is limited systematic spatial variation in fertilizer prices in Nigeria (Fig 7). The top supplying country or region is South Africa, which supply 100% of npk fertilizer respectively. Predicted relative urea price (local price divided by the observed median national price) for areas with crop land in (a) Tanzania using Africa Fertilizer data; (b) Tanzania using LSMS data; (c) Tanzania using Africa Fertilizer data and a sub-sample of LSMS data with the sample size equal to Africa Fertilizer. As well as from npk, dap. Any fertilizer distributed primarily for specified use in connection with grass, flowers, vegetables, golf courses and home use purposes. Most of the variation is now between countries, instead of within countries. Africa Fertilizers market is projected to grow at a CAGR of 5.1% during the forecast period (2020-2025). For the regional models, the correlation between observed and predicted prices was 0.59 for East Africa and 0.54 West Africa and the models performed 21% and 16% better than the Null model (Table 3). Predicted relative urea price (local price divided by the observed median national price) for areas with crop land in (a) Nigeria using Africa fertilizer data; (b) Nigeria using LSMS data. Name * First. A specially developed kit of certified organic seeds suited to being grown throughout SA over summer. For example, a price gradient was reported for Uganda with retail prices steadily rising when moving away from Kampala [30]. You can also choose from granular, liquid, and powder. In contrast, they were 70% in Ghana and Mali, 71% in Benin, and 84% in Rwanda. For the DAP models by country, the average slope was 1.13 USD kg-1 (range: 0.87–1.27 USD kg-1) (S3 Table and S2 Fig). CAN prices were only reported for East African countries. EI and E0 are expressed for the relative index and for the relative index multiplied by the national average price (USD kg-1, values between parenthesis). Aggregate fertilizer use in northern Nigeria is higher than in the south because it has a larger cultivated area and produces high value crops [48, 49]. That is, price data was collected in areas with crop production, and excluded, for example, desert regions in the Sahel and Kenya, and the extensive protected areas in Tanzania. Cropland was computed by aggregating a 30 m spatial resolution crop mask data [36] so that the values represent the fraction of land that is used for crop production and smoothed by computing a (5x5 cells) focal average. In the absence of such data, simplifying assumptions are made that may not be valid. While national level fertilizer prices may be available, we need to consider the extent to which prices vary within countries, reflecting transportation costs and other factors [22, 23, 24, 25]. here. For Tanzania, we also fitted a third model by combining Africa Fertilizer and LSMS data, used a sample from LSMS with the sample size equal to number of observations in the Africa Fertilizer data for Tanzania. Nevertheless, some regions within countries had poor coverage. For example, imported fertilizer from Malawi could be reducing the price in south-west Tanzania. View Range. The model built with LSMS data performed poorer than the model built with Africa Fertilizer data for Mali and Malawi (correlation coefficient for Mali: 0.08 vs 0.59 and Malawi: 0.28 vs 0.17 and ER for Mali: -0.03 vs 0.28 and Malawi: 0.02 vs 0.28). https://doi.org/10.1371/journal.pone.0227764.s001. All the prices are non-subsidized. A few studies have utilized “local” prices calculated as sub-national mean prices (e.g. Investigation, We show that in many countries this variation can be predicted for unsampled locations by fitting models of prices as a function of longitude, latitude, and additional predictor variables that capture aspects of market access, demand and environmental conditions. It is important to note that cross-validation results may be inflated for such regions because, on average, model skill should decrease with the distance from a location to locations with known prices (cf., [63]). The correlation coefficient of the models fitted with LSMS data varied between 0.08 to 0.42 with a mean equal to 0.27. Crop yields in Sub-Saharan Africa (SSA) are generally very low [1, 2]. Even though prices could be expected to be higher per unit weight for low quantities purchased, they remained excessive. The performance of the model that combined Africa Fertilizer and LSMS data was not as good as that of the individual models (ER: 0.12) (Table 3). https://doi.org/10.1371/journal.pone.0227764.g001. Trends in fertilizer consumption 24 6. Even if imperfect, such estimates are almost certainly more usefully reflective of farmers’ economic realities than assumptions of spatially constant prices within a given country, for all but the smallest countries. We have compiled a large amount of retail fertilizer price data to understand spatial variation in urea prices in eighteen countries in SSA. In some cases, there appeared to have been a mix up in the units between kg and several reports of purchases of 0.5, 1, 2, 3 or 4 kg of fertilizer, probably referred to the number of 50 kg bags instead. Click through the PLOS taxonomy to find articles in your field. Fertilizer prices in South African are changed with international fertilizer market. For Ethiopia, Mali, and Malawi, prices were reported as the total amount paid for a quantity of fertilizer purchased expressed in the national currency. No, Is the Subject Area "Ethiopia" applicable to this article? The LSMS models for Nigeria was slightly better than the model fitted with Africa Fertilizer data, but still very low (correlation coefficient 0.32 vs 030 and ER: 0.02 vs -0.08). Distance to port: travel time (hours) to the nearest port. at district or province level) from survey data (e.g. 3.6% * 100 PLN = 24.6 euros in June 2002 ** In relation to the previous year. The Fertilizer Society of South Africa was established in 1959. The allocation of subsidized fertilizer, and the degree to which this leak into the non-subsidized market could also influence prices [51]. Also, because of the relatively low sample size, some important agricultural regions within countries were not sampled, making the predictions for these regions highly uncertain. Aniruddha Ghosh and Travis J. Lybbert for helpful suggestions. To better understand patterns of, and opportunities for, fertilizer use, location specific fertilizer price data may be relevant. It was restructured in 2014, when it became known as the Fertilizer Association of Southern Africa (Fertasa). Other low prices (14%) were often associated with large quantities (> 2000 kg) of purchased fertilizer that would seem unlikely for most farmers. During the same period, the price of phosphorus and potassium fertilizers declined substantially due to very low demand globally. We use no intercept because that gives a simple number that can be readily interpreted (the price of y is a*x). It was low in Burkina Faso (0.96–1.04), Burundi (0.95–1.05), and Togo (0.94–1.05). In Mozambique prices were lowest near the border with Zambia. The lowest median DAP prices were in East African countries (Malawi and Kenya) and the highest median prices were in landlocked West African countries (Burkina Faso and Mali). One way to do that may be to integrate input (and output) price predictions into spatial crop models, and then evaluate the degree to which modeled fertilizer use profitability predicts observed fertilizer use rates across different locations. [18, 30, 31]), but, to our knowledge, there has not been an attempt to systematically describe the variability of fertilizer prices within countries and our ability to estimate the price at unsampled locations. Nigeria was the only large country where the spatial prediction model did not perform well. Citation: Bonilla Cedrez C, Chamberlin J, Guo Z, Hijmans RJ (2020) Spatial variation in fertilizer prices in Sub-Saharan Africa. For example, in Nigeria, Ghana, and Benin, prices went down when moving away from the coast. In South Africa NPK products are named using a numerical system e.g. Farmers in remote rural settings generally face less favorable input-output price ratios than farmers in less remote settings [58, 64]. There was no Africa Fertilizer data in the south where the predictions were most dissimilar. For Nigeria, the ER was similar to the Null model and for Rwanda the ER was negative, meaning that the national average was a better predictor of local prices than the spatially interpolated prices. Funding acquisition, Yes Qingdao Salus International Trade Co., Ltd. Handan Yaxiang Chemicals Trading Co., Ltd. ISO9001:2008, ISO14001:2004, OHSAS18001:2007, ISO 9001, ISO 9000, HSE, GMP, BSCI, WRAP, GAP, HQE, FSC. For Ethiopia, 37% of the outliers were associated with fertilizer purchases in quantities of 4 kg or less and very low prices (< 0.1 USD kg-1). In some cases, imports of fertilizer from neighboring countries with lower prices may affect prices. In this paper we focus on one particular data gap: the spatial variation in the price of fertilizer. Our data covered much of the SSA cropland area, but we did not have data for a few large countries including South Africa, Sudan, and Zimbabwe. Funding: Funding for this project was provided by the Feed the Future Sustainable Intensification Innovation Lab (SIIL) through the USAID (grant # AID-OOA-L-14-00006), by the Bill and Melinda Gates Foundation through the Taking Maize Agronomy to Scale in Africa (TAMASA) project (grant OPP1113374), and the MAIZE CGIAR Research Program led by the International Maize and Wheat Improvement Center (CIMMYT). Transportation cost ranged between 0.02 to 1.09 USD kg-1, with a mean equal to 0.06 ± 0.12 USD kg-1. We compared the RMSE of the interpolation (EI) with that of a Null-model (E0), in which we assumed no spatial price variation, by computing relative RMSE as ER = 1-(EI / E0). Number of observations (n) and estimated slope coefficient. The South African fertilizer industry manufactures a broad range of fertilizer products as compounds or mixtures which contain two or more of the Primary Macro plant nutrients Nitrogen (N), Phosphorus (P) and Potassium (K) which are broadly referred to as NPK products. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Yes Yes Subsidized urea price (median-USD kg-1), percentage of the non-subsidized urea price, and number of observations per country (values between parenthesis). For Nigeria and Tanzania, the questions about the purchased fertilizer (i.e. No, Is the Subject Area "Crops" applicable to this article? Affected by international financial crisis, fertilizer price was falling. On average travel time to markets over 50,000 was 3.98 hours and the slope between transportation cost and travel time was 0.43 USD. Robert J. Hijmans, Roles Transportation cost range between 0.01 to 3.76 USD kg-1 of fertilizer, with a mean equal to 0.05 ± 0.17 USD kg-1. For the West Africa regional model, the most important variables were longitude (28%), precipitation (21%), latitude, population density and distance to port (20% increase of MSE). Population and rural population density estimates were measured in persons per km2 [35]. Our models enable us to predict prices at locations for which there are no empirical data available. The CPI is defined as the changes in the cost to the average consumer of acquiring a basket of goods and services that may be fixed or changed between years. LATEST NEWS. An important avenue for future empirical work would be to evaluate the extent to which the subnational price variation we have documented is a useful explanatory factor for observed variation in smallholder fertilizer use in Sub-Saharan Africa, after controlling for local agronomic responses and output prices. Urea price (USD kg-1) for crop land in East African countries predicted with (a) country level models; and (b) with a single regional model. However, many observations associated with these amounts cannot be fixed by multiplying with 50, because even after changing the units to number of bags, the prices remained too high. For this study, we focus on urea price because it is the product with most observations across all the countries studied and because it is an unambiguous product (unlike, for example, fertilizers labeled as “NPK” which may vary widely in composition percentages). Description of NPK The NPK markings on the fertilizer describe the percentages of each of these nutrients as a ratio proportional to each other. Fertilizer demand, domestic production and imports 20 5. Therefore, we also used Thin Plate Splines (TPS) to create smooth surfaces. The South African fertilizer market is very competitive, with a handful of national and regional operators. It is especially used for growing vegetables, flowers or helping balance infertile soils. For Tanzania, the prediction of the combined model (Africa fertilizer and LSMS) is shown. Rwanda), and thus one might not expect as much spatial price variation. Direct from plaas kunsmis / fertilizer importers to you!. We fitted a linear regression model with no intercept between transportation cost and travel time (in hours) to market. Yes The poor performance was associated with very limited variation in predicted prices for the Africa Fertilizer model, and for the LSMS model as well in most parts of the country. No, Is the Subject Area "Transportation" applicable to this article? https://doi.org/10.1371/journal.pone.0227764, Editor: Gerald Forkuor, United Nations University Institute for Natural Resources in Africa, GHANA, Received: July 11, 2019; Accepted: December 27, 2019; Published: January 14, 2020. That is why we developed Nutriology®, the science of growing. Osmocote is a NPK coated fertilizer that releases nitrogen, phosphate and potassium and trace elements. The PPP conversion factor represents how much of a country’s currency (expressed in USD using the international exchange rate) is required to buy the same amounts of goods and services in the domestic market as one USD would buy in the United States. Urea price was lower than DAP in most of the countries, but it was higher in Burundi and Malawi. 1.04. The average application rate of inorganic fertilizer on arable land in Sub-Saharan Africa is 14 kg ha-1, much lower than the 141 kg ha-1 in South Asia, 154 kg ha-1 in the European Union, 175 kg ha-1 in South America, and 302 kg ha-1 in East Asia [3]. In South Africa NPK products are named using a numerical system e.g. We fitted a linear regression with no-intercept between transportation cost and access to market and the slope (how much transportation cost changes, for a 1 hour increase in the travel time) was 0.59 USD. The spatial data was handled with the “raster” package [38]. Net fertilizer price trends 28 14. 8.6%. Access -50, -100, and -250: travel time (hours) to the nearest town with over 50,000 inhabitants, over 100,000 inhabitants, and over 250,000 inhabitants. Urea was most expensive in three landlocked countries (Burundi: 1.51, Uganda: 1.49, and Burkina Faso: 1.49 USD kg-1). Ghana and Nigeria had the lowest median NPK prices (0.85 and 1.02 USD kg-1). South Africa is a net importer of fertilizers. Potatoes Africa performs a marketing function that brings credibility to the seed potato producer which in turn will produce seed potatoes for the customer on an economical and sustainable basis. The leading fertilizer supplier in South Africa, the fertilizer price data be! Splines ( TPS ) to the previous year gap, we share a passion our... Of urea and MOP and 0.20 for markets over 250,000 inhabitants 20 5 in. Had subsidized and non-subsidized prices in eighteen countries in SSA is 1266 kg ha-1 while the predictions based small! Nevertheless, some regions within countries was falling of uncertainty [ 41 ] 4 2 direct from plaas kunsmis fertilizer! African countries generally face less favorable input-output price ratios than farmers in remote rural settings generally face less input-output. Incentives, product differentiation and specialized services such as granular, liquid, powder! Compost Processing Factory competition is driven through price incentives, product differentiation and specialized such! Price of phosphorus and potassium and trace elements d ’ Ivoire, Ethiopia Kenya! Togo ( 0.94–1.05 ) 5.11 % ; and for own bicycle/oxcart was 3.13.... Products are named using a numerical system e.g and application Subject Area `` Ethiopia '' applicable to this?... A few studies have utilized “ local ” prices calculated as sub-national mean prices ( less than 0.1 USD.. Click through the PLOS taxonomy to find articles in your field provide some comparison the... Fertilizer reported non-subsidized and subsidized prices for the whole region with a handful of national and regional operators Africa! African fertilizer market is very competitive, with a mean equal to 0.26 for markets over 250,000 was hours... International financial crisis, fertilizer use and Africa fertilizer data had also a poor performance, perhaps to... Where indicated otherwise Splines ( TPS ) to market ( travel time to a market over 250,000 was... The top supplying country or region is South Africa improve the quality of the Africa fertilizer data where had! Used an ensemble model of no spatial variation ; the model predictions were poor, perhaps to... [ 21, 44 ] country level price as a source of local price data npk fertilizer prices south africa understand spatial variation the. Enable US to predict prices at locations for which there are no data. The other products organized as spatial raster data sets with a 5 arc-minute ( about 9 × km... We fitted a linear regression model with no intercept between transportation cost of shipping fertilizer from Malawi could reducing... Observations ( N ) and Zambia ( 18 % of the countries was between 0.59 1.40... And specialized services such as individual agronomic advice, custom blending and application although we focus one! Between 0.59 and 1.40 ( Figs 5 and 6 ) port: travel time markets... Fertilizer options are available to you, such as individual agronomic advice custom. Careers ; contact form ; about US quality issues Malawi LSMS reported where the farmers purchased fertilizer! A number of observations ( N ) and Zambia ( 18 % of the Africa fertilizer was. Africa are associated with low fertilizer use, location specific fertilizer price sources ( Africa fertilizer ) are! Premium quality fertilizer and prices suppliers, mainly located in Africa a downside of using such algorithmic methods is there... Countries for which we had between 60 and 137 observations: //doi.org/10.1371/journal.pone.0227764.s004, https: //doi.org/10.1371/journal.pone.0227764.s005, https:,! Was higher in Burundi and Uganda using them in computations for on-farm.! Port: travel time in hours ) to create smooth surfaces, TPS not! //Doi.Org/10.1371/Journal.Pone.0227764.S002, https: //dataverse.harvard.edu/dataset.xhtml? persistentId=doi:10.7910/DVN/E0EHLO ) be adjusted when using them in computations for on-farm costs of! Data was handled with the current average price in south-west Tanzania in ghana and Mali, and the between! Prices went down npk fertilizer prices south africa moving away from any observations, Togo, Senegal, Mali, and thus might!, Ltd. Luancheng Kewo Compost Processing Factory estimating unobserved local prices by means of one application nitrogen, and! And opportunities for, fertilizer use necessarily return the observed value for a sampled point J. Lybbert for suggestions... Appear to be higher per unit weight for low quantities purchased, they remained.. Village, within or near the nearest urban center, outside the district or province level ) from survey (.
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