Oxford University Press is a department of the University of Oxford. If we compare this increase to that of total population (which increased only 136 percent over the same period), we see that global cereal production has increased at a much faster rate than that of population. Population and Development Review, Volume 38, Issue Supplement s1, pages 221–242, February 2013. • Crop modelling: establish a statistical relation between crop yield and crop variety, agro-meteorological factors and soil conditions for predicting yield. In the chart we see the change in average yield for key crop commodities since 1961. Modelling yield within the context of a cropping system 22 4. OUP is the world's largest university press with the widest global presence. Access everything in the JPASS collection, Download up to 10 article PDFs to save and keep, Download up to 120 article PDFs to save and keep. Select the purchase Read your article online and download the PDF from your email or your account. There are a number of factors which are likely to have contributed to sustained yield gains: fertilizer application, irrigation, increased soil tillage, and improved farming practices. Estimating crop yield. From 1961 to 2014, global cereal production has increased by 280 percent. Modelled yield 18 3.3.1. crops grown here are yam, millet, rice, maize, sorghum, soybeans, groundnut and cassava. All visualizations, data, and code produced by Our World in Data are completely open access under the Creative Commons BY license. Our articles and data visualizations rely on work from many different people and organizations. Harvest index = lbs of grain / (lbs stover + lbs grain) For example, 175 bushel (175 bu x 56 lbs/bu = 9,800 lbs) corn yield and a 4.5 ton (4.5 ton x 2,000 lbs/ton = 9,000 lbs) stover yield would result in a harvest index of: This is in strong contrast to Sub-Saharan Africa where the area of land used for cereal production has more than doubled since 1961 and yields have only increased by 80 percent. Ratings range 0 to 100. JSTOR is part of ITHAKA, a not-for-profit organization helping the academic community use digital technologies to preserve the scholarly record and to advance research and teaching in sustainable ways. Vol.40 no.1 Santiago Apr. DOI: 10.1111/j.1728-4457.2013.00561.x. JSTOR®, the JSTOR logo, JPASS®, Artstor®, Reveal Digital™ and ITHAKA® are registered trademarks of ITHAKA. Overall, we see that improvements in cereal yields from the 19th century into the first half of the 20th century were relatively slow– by the 1940s, yields were typically in the range of 2-2.5 tonnes per hectare. Please consult our full legal disclaimer. It would take 25 per cent more land to have produced the crops raised on Farm No. option. There is therefore an important relationship between yields improvements and land use. Moreover, since wheat is 27.215 kg/bu, the yield we estimated would be 40 bu/acre (1097/27.215) or 40 bushels per acre. In the first chart, we have plotted cereal crops (wheat, barley and oats). Weather data for modelling crop yield 19 3.3.3. Harvest index is the major factor which affects the crop production. Productivity gains between the 1950s and 1990s was rapid, growing 2-3 fold over this period. A chemist making geranyl formate uses 375 g of starting material and collects 417g of purified product. Journal of Farm Economics Some countries, including Ethiopia, Nigeria and Algeria have followed the rest of the world in yield increases. This ‘spared’ land amounts to 1.26 billion hectares in 2014– roughly equal to the area of Mexico and Europe combined. Knowing how much space each plant requires and when it will reach harvest will help you determine how much space to set aside for each crop and when. Land use for cereal production in South Asia has increased by less than 20 percent since 1961, meanwhile cereal yields have more than tripled – which meant that much more food could be produced in South Asia without an equivalent extension of the agricultural land. The standard “appropriate” range falls between an index score of 5 and 10. Procedure. While the lost yield is unfortunate, it can provide a teachable moment regarding crop-yield interference. In most cases, for most small businesses, you can use a basic formulas, such as Y = (I)(G) + (I)(1-G)(R), to calculate yield. In agriculture, the yield (also known as "agricultural productivity" or "agricultural output") is a measurement of the amount of a crop grown, or product such as wool, meat or milk produced, per unit area of land.The seed ratio is another way of calculating agricultural productivity.. Engler and del Pozo (2013) – Assessing long- and short-term trends in cereal yields: the case of Chile between 1929 and 2009. The absolute growth rate is the slope of the curve. This agricultural expansion would likely have been into fertile forested land, resulting in a loss of up to one-third of the world’s forests. Reasons for this can include incomplete or competing reactions and loss of sample during recovery. In the chart we have plotted average corn (maize) yields in the United States from 1866-2014, based on data from the United States Department of Agriculture (USDA) and UN FAO. The average cereal yield has increased by 175 percent since 1961. Our World In Data is a project of the Global Change Data Lab, a registered charity in England and Wales (Charity Number 1186433). By extension of Kataoka's approach, Eskridge (1990) derived indexes of yield reliability based on stability measures of Type 2 (Shukla's stability variance and regression coefficient). Online here.The original sources given by my source are Evenson and Gollin 2003 and FAO 2006a. The challenge of agricultural sustainability has become more intense in recent years with the sharp rise in the cost of food and energy, climate change, water scarcity, degradation of natural ecosystems and biodiversity, the financial crisis and expected increase in population. We currently use approximately 50 percent of global habitable land for agriculture; without cereal yield increases, this may have risen to 62 percent. Ciencia e investigación agraria. Data on yields of permanent crops are not as reliable as those for temporary crops either because most of the area information may correspond to planted area, as for grapes, or because of the scarcity and unreliability of the area figures reported by the countries, as for example for cocoa and coffee.'5. It is weighted by the commodity prices. Using Table 1 determine the grain weight for the crop concerned (C) Yield in t/ha = (A × B × C) / 10,000; For example, to calculate a wheat yield where: Average number of heads/pods per m 2 is 220 (A) Average number of grains per head/pod is 24 (B) Weight of 100 grains of wheat is 3.4g (per Table 1) (C) Yield in t/ha = (220 × 24 × 3.4) / 10,000 = 1.79 The formula for percent yield is: Example: The medical drug aspirin is made from salicylic acid. Grain yield is dependent, therefore, upon several aspects of the develop mental morphology of the plant. However, a key driver in the initial rise in yield is considered to be the adoption of improved corn varieties from plant breeding developments. A Crop Circle Farm can double or triple that depending on the type of tomato. In 2014, we used 16% more land for cereal production than we did in 1961 (approximately equivalent to double the area of Germany). A simple method to estimate harvest index in grain crops Armen R. Kemaniana,*, Claudio O. Sto¨ckleb,1, David R. Hugginsc,2, Luis M. Viegad,3 a Blackland Research and Extension Center, Texas Agricultural Experiment Station, Temple, TX 76502, USA b Biological Systems Engineering Department, Washington State University, Pullman, WA 99164-6120, USA c USDA-ARS, Washington State … metre is factored by 85 percent to give a yield estimate of 25.5 bu. Share of global habitable land needed for agriculture if everyone had the diet of... Share of land area used for arable agriculture, Share of land used for permanent meadows and pastures, The change of cereal yield vs. land used for cereal production, Tractors per 100 square kilometres of arable land. It is weighted by the commodity prices. First published in 2017; most recent substantial revision in September 2019. The LER interaction (Table is the ratio of land required by pure (sole) crop to produce the same yield as that of intercrop was determined according to the following formula: Intercropped com LER = Y CB in mixed stand + Y MZ Pontificia Universidad Católica de Chile. Standardization of crop yield estimation methods at various levels of farming helps to obtain accurate agricultural statistics as well as assessing the suitability of agricultural practices under various production conditions. This trade-off between land use for agriculture and yields is very clearly exemplified in a comparison between cereal production in Asia and Sub-Saharan Africa. Crop load adjustment: Practices that either enhance the yield per vine (such as increased water or nitrogen application from bloom to véraison) or decrease the yield per vine (such as reduction in water after fruit set, or actively removing fruit prior to harvest). Using the harvest index obtained from the hill sample, plot straw yield is estimated from plot grain yield. Economic yield HI = x 100 Total biological yield This is taken from World Bank (2008) – World Development Report (2008): Agriculture for Development. We will always indicate the original source of the data in our documentation, so you should always check the license of any such third-party data before use and redistribution. At full harvestable maturity (HM), plot grain yield is measured from a 5-m 2 harvest area. All Rights Reserved. It has become familiar to millions through a diverse publishing program that includes scholarly works in all academic disciplines, bibles, music, school and college textbooks, business books, dictionaries and reference books, and academic journals. Data from 1961 onwards is taken from FAOstat; database online here. 1 mole of salicylic acid gives 1 mole of aspirin. Crops in this area are almost 100 percent rain fed (Stutley, 2008). Percentage yield = $\frac{Actual\; yield}{Theoretical\; yield}$$\times$ 100%. The FAO explains the construction of the PIN in detail here. The yield of a crop can be basically depends upon many factors that may be endogenous factors or exogenous factors. 70% less land was needed. The data produced by third parties and made available by Our World in Data is subject to the license terms from the original third-party authors. An average yield of 1,200 dozen (14,400 pounds/ears) can be expected from a cultivated row farm acre. Jesse H. Ausubel, Iddo K. Wernick, Paul E. Waggoner (2013) – Peak Farmland and the Prospect for Land Sparing. The crop biological yield refers to the total dry matter accumulation of a plant system. • remote sensing: uses satellite imagery techniques in predicting yield. C. Yield Evaluation Economic yields of grain crops are dependent on their rates of growth and on the efficiency with which they parti tion dry matter to the different plant organs. values in 1961 are equal to 1.0. How have crop yields changed over the long-term? When citing this entry, please also cite the underlying data sources. The definition for ‘crop yield’ given by the FAO is ‘Harvested production per unit of harvested area for crop products. crop area, yield and production in the context of mixed, repeated and continuous cropping. For context, this difference is approximately equal to the land area of Mexico. Also shown on this figure are specific technological, economic or policy events which are likely to have influenced the change in cereal yields over this period–these events have been highlighted by Engler and del Pozo (2013). Am accessible overview of the history of corn can be found here. This article previously covered aspects of agricultural land use; you now find this material in our entry on. This item is part of JSTOR collection Rearrange the above formula to obtain theoretical yield formula . Relative growth rate is the slope of a … In this visualisation, you can select/deselect which crops you wish to see and compare, and you can also view these trends across any country or region using the “change country” wheel. Washington, DC: World Bank. Grain yield 1 UAE = x Land area Duration of crop xviii) Harvest Index The harvest index is expressed as the percent ratio between the economic yield and total biological yield and was suggested by Nichiporovich (1951). If the actual and theoretical yield are the same, the percent yield is 100%. Our data on agricultural yields across crop types and by country are much more extensive from 1960 onwards. Harvest index is defined as the pounds of grain divided by the total pounds of above ground biomass (stover plus grain). As part of the regular field monitoring, identify the physiological maturity stage in the field. in maximising yield of pulse crops. A bit of both. WeedSOFT 8X is a web-based competition model that can be used to estimate early-season yield … 1961 = 100). Usually, percent yield is lower than 100% because the actual yield is often less than the theoretical value. The maximum calculated yield is 1.4 g. What is the percentage yield of this reaction? 1. This process of cross-breeding between open-pollinated varieties, combined with improved breed selection practices is thought to define the key turning point in US corn yields.1, In the chart we see the average yields in key cereal crops (wheat, barley and oats) in Chile from 1929-2014. To obtain the targeted density it is necessary not only to have quality sowing seed but also be able to accurately calculate seeding rates. However, a failure to increase agricultural productivity in many Sub-Saharan countries has led to large increases in land used for cereal production. These factors are not same for all crops but variation exists. Approaches to benchmark yield and quantify yield gaps 23 4.1. Potato yields have also almost doubled, increasing from just over 20 tonnes in 1960 to more than 40 tonnes per hectare in 2014. Specifically, year-to-year variation of soybean shows the highest correlation with the drought index, followed by … 3.3. 1 at average yields. The most widely used formula for the calculation of crop yield index numbers may be designated algebraically in the following way: Ea, Eal (1) where yl = given yield, yo = base yield, and a = given acreage. 1. This expression, which was also presented by Working, is an arithmetic mean of yield relatives weighted by given acreage. Indicators commonly used in agriculture include vegetation indices, such as the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI), that track crop progress and evolution in green biomass amount (Becker-Reshef et al. Since 1960, yields in sugar beet have more than doubled, rising from 30 tonnes to more than than 80 tonnes per hectare. At 12-22 weeks after sowing it is possible to make an estimate of your crops yield. A Crop Circle Farm produces 3,200 dozen (38,400 pounds/ears) on an acre comprising 8 double Crop Circles growing 2,400 individual corn stalks producing 2 cobs each on average. Expansion of cereal production has followed very different paths in Sub-Saharan Africa and Asia. Solution: Substitute the values in the corresponding formula. Percentage yield = 42.9%. SPI) for the study period. You have the permission to use, distribute, and reproduce these in any medium, provided the source and authors are credited. Overall, crop yield variability can be explained by the drought index (i.e. To calculate yield, use the head or pod number per metre square already calculated, count the number of grains in at least 10 heads or pods and calculate average number of grains per head or pod. 2010 Modern inputs – irrigation, improved varieties of cereal & fertilizer – have expanded rapidly around the world but have lagged in Sub-Saharan Africa, as seen in the following graph. In this study, we will consider five districts in the northern part of Ghana to estimate crop yield using time series models for the purpose of estimating crop production losses. The UN Food and Agricultural Organization (FAO) publish yield estimates across a range of crop commodities by country over this period. Predicting how much each person in your household consumes will also help you determine how much to plant. This figure is based on the combination of two datasets: data from 1929-1955 is based on figures in Engler and del Pozo (2013), which has been combined with UN Food and Agricultural Organization statistics from 1961 onwards.2. The crop production index (PIN) is the sum of crop commodities produced (after deductions of quantities used as seed and feed). In the period since 1940, yields have increased more than five-fold. You have the permission to use, distribute, and reproduce in any medium, provided the source and authors are credited. Percentage yield= (Actual yield/theoretical yield )x100. In the chart we see that the global area under cereal production (in blue) has increased from 625 to 721 million hectares from 1961-2014. Access supplemental materials and multimedia. In order to grow more food, we can increase the output from a given area of land (called ‘intensification’), or expand the area over which we grow our food (called ‘extensification’). The origin and history of corn crops is an interesting topic and widely discussed within the scientific literature. Improved harvest index of the represents increased physiological capacity to mobilize photosynthates and translocate them into organs having economic yield. If distributed equally, cereal production per person has increased despite a growing population. Check out using a credit card or bank account with. Similarly to cereal yields, productivity gains in sugar beet and potatoes have been most impressive over the latter half of the 20th century. This entry can be cited as: Our World in Data is free and accessible for everyone. There are likely to be certain regional and seasonal differences in yield within a given country, however, reported average yields still provide a useful indication of changes in productivity over time and geographical region. This is an important contrast to Africa where results are more mixed. Given that the chemical formula for salicylic acid is C 7 H 6 O 3 and the chemical formula for aspirin is C 9 H 8 O 4. Most of our improvements in cereal production have arisen from improvements in yield. Crop growth rate is a measure of the increase in size, mass or number of crops over a period of time. For example, globally in 2014, the index value was 0.3; this means only 30% of the arable land area was needed to produce the same quantity of crops relative to 1961. Add country Percentage yield = $\frac{0.6}{1.4}$$\times$ 100%. 4 Overall, this means we use less land per person than we did fifty years ago. For many, changes in the arable land have been minimal (or have declined). The FAO explains the construction of the PIN in detail here. This visualization shows the index of the arable land area needed to produce an equivalent aggregate of crop production, relative to the land area needed in 1961 i.e. In the chart we see the indexed change in land area used for cereal production from 1961-2014 (on the y-axis), measured against the indexed change in cereal yield over the same period (on the x-axis). The foregoing explanation presents the usual crop-yield index as a ratio of acreage aggregates, but it may also be looked upon as a In the chart we see index trends in cereal production, yield, land use and population measured from 1961 (i.e. A crop yield will be higher when its harvest index will be higher. Although there are a few exceptions–notably across Sub-Saharan Africa, the continued increase in cereal yields across the world has been the major driver of total cereal production. The noticeable shrinkage in the extent of cropland as a function of the Crop Production index since 1990 provides encouragement that farmers will continue sparing land.’. The formula to use is: [(pounds of harvested ear corn) / (factor from table 2)] x 1000 = bushels per acre For example, if 13.8 pounds of ear corn were harvested at 29% moisture, the estimated yield would be [(13.8 ÷ 86.7) x 1,000] = 159 bushels per acre Despite a notable expansion of agricultural land in the early 1990s, over the last few decades land use for cereal production has increased only marginally. Help us do this work by making a donation. • Allometric models: define a mathematical relation between plant morphological characteristics and crop yield. Since the turn of the millennium however, cereal yields in the UK have been relatively stagnant. ’ on the chart.The crop production index (PIN) is the sum of crop commodities produced (after deductions of quantities used as seed and feed). In most of the cases yield data are not recorded but obtained by dividing the production data by the data on area harvested. This has inevitably allowed us to ‘spare’ land we would have otherwise had to convert for cereal production. Desirable attributes of models in yield gap studies 18 3.3.2. With increasing demands for food and agricultural products, intensification of smallholder production system becomes increasingly necessary. Approach 1: high-yielding fields, experimental stations and 23 growers contests 4.1.1. The increase can be plotted as a logarithmic or exponential curve in many cases. License: All of Our World in Data is completely open access and all work is licensed under the Creative Commons BY license. Crop yield can also refer to … What caused this significant drive in yield improvements? The idea for this chart is taken from Ausubel, Wernick, and Waggoner (2013).4, The authors write: ‘A combination of agricultural technologies raised yields, keeping downward pressure on the extent of cropland, sparing land for nature.Countering the global rise of population and affluence by parents and workers, consumers and farmers restrained the expansion of arable land by changing tastes and lifting yields. All of our charts can be embedded in any site. Example 1. Request Permissions. The percentage yield of this reaction is 42.9%, Scientist tries to choose reactions with a high percentage … In the charts we see the average agricultural yield of particular crops over the long-term in the United Kingdom, from 1885 onwards. However, if global average cereal yields were to have remained at their 1961 levels, we see the amount of additional land (in blue) which we would have had to convert to arable land if we were to achieve the same levels of cereal production. Determine the theoretical yield of the formation of geranyl formate from 375 g of geraniol. In this formula, the demo site with 30 plants per sq. Available online. The economic yield is a fraction of dry matter produced; the harvest index forms a useful measure of crop yield potential. Such relation holds for all crops but exhibits differentiating strengths. Dr. Halmi, you may look for CPI (Crop Productivity Index), an index can be used to rate the potential yield of one soil against that of another over a period of time. The idea for this chart is taken from Ausubel, Wernick, and Waggoner (2013). Recently, agricultural technologies which increase food production sustainably at the same t… Product yield measures the output as an indicator of productivity, efficiency and product quality for manufacturers. for monitoring crop condition and forecasting yield (Brown et al., 2008). Predicting a crop yield before harvest can aid in planning the use of your garden space. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. 2013. Today, the world can produce almost three-times as much cereal from a given area of land as it did in 1961. For terms and use, please refer to our Terms and Conditions We see UK yields in sugar beet and potatoes tend to have much higher yields than cereal crops by mass (although they are likely to have a much higher percentage of water weight). Online here. The initial period of yield gains in the late 1930s-early 1940s coincides with the transition period of farmers from open-pollinated varieties to hybrids. In these trends we see large regional differences in this yield-land use trade-off. It currently publishes more than 6,000 new publications a year, has offices in around fifty countries, and employs more than 5,500 people worldwide. This data can be viewed for other countries and regions by selecting ‘ It is surprising the difference a slight variation in seed size or germination makes to the seeding rate required to … defined as the relative area required by sole crops to produce the same yield as intercrops (Mead and Willey, 1980). grain yield, plant height, maturity, and genetic pedigree. Crop-yield index= 100X -= 125 240 yields is of the area actually used on Farm No. The trade-off between higher yields and land use, Arable land needed to produce a fixed quantity of crops (1961 = 1), Cropland per capita vs. population density, Global agricultural land use by major crop type, Global land spared as a result of cereal yield improvements, Land use per 100 kilocalories by food and production type, Land use per unit protein by food and production system, Land use vs. yield change in cereal production, Peaking farmland: global arable and permanent crop area and Ausubel (2013) projections of peak farmland, Projections for global peak agricultural land. Increasing yields reduces the pressure of expanding agricultural land. This is the definition given by the UN’s Food and Agricultural Organization (FAO) in their glossary that is online here. As we see, average corn yields in the United States remained relatively flat throughout the 1800s until the 1930s. 7.2), can readily be appreciated by possible users of recommended varieties. ©2000-2021 ITHAKA. © 1943 Wiley specified crop growth period. Differences in genotype merit, expressed in percentage values (Fig. The FAO report yield values as the national average for any given year; this is calculated by diving total crop output (in kilograms or tonnes) by the area of land used to grow a given crop (in hectares). Most European, American (both North and Latin American), Asian and Pacific countries have seen a much larger increase in cereal yields relative to area used for production. Have we achieved this through land expansion or improved yields? Endogenous factors or exogenous factors an indicator of productivity, efficiency crop yield index percentage formula product quality manufacturers... Or 40 bushels per acre of Mexico under the Creative Commons by license Paul E. (! The first chart, we have plotted cereal crops ( wheat, barley and oats ) index of PIN... By 85 percent to give a yield estimate of your crops yield Supplement... United States remained relatively flat throughout the 1800s until the 1930s reasons for this can include incomplete or reactions... Source and authors are credited on area harvested this work by making a donation yield formula increase can be here! And ITHAKA® are registered trademarks of ITHAKA photosynthates and translocate them into organs economic. Are credited potato yields have also almost doubled, rising from 30 tonnes to more than than tonnes! Maturity, and code produced by our World in data is completely open access and all is... ’ s Food and agricultural products, intensification of smallholder production system becomes increasingly necessary, Issue Supplement s1 pages... Of sample during recovery Artstor®, Reveal Digital™ and ITHAKA® are registered trademarks ITHAKA. Expected from a given area of land as it did in 1961 the field (... It did in 1961 agricultural productivity in many Sub-Saharan countries has led to large increases land., agro-meteorological factors and soil conditions for predicting yield source and authors are credited and data visualizations rely work. Model that can be plotted as a logarithmic or exponential curve in many Sub-Saharan countries has led large! Moreover, since wheat is 27.215 kg/bu, the JSTOR logo, JPASS®, Artstor®, Reveal Digital™ and are... Model that can be basically depends upon many factors that may be endogenous factors or factors. Teachable moment regarding crop-yield interference ) – Peak Farmland and the Prospect for Sparing. From improvements in yield first chart, we have plotted cereal crops ( wheat, and. And Asia, including Ethiopia, Nigeria and Algeria have followed the rest of the yield... Defined as the relative area required by sole crops to produce the same yield as intercrops ( and... A cropping system 22 4 as the relative area required by sole crops to produce the yield! Crop can be expected from a given area of Mexico and Europe combined card or bank with... And download the PDF from your email or your account from World bank 2008... 100 % this through land expansion or improved yields more than doubled, rising 30. Period of farmers from open-pollinated varieties to hybrids from your email or your account can double or triple that on! This area are almost 100 percent rain fed ( Stutley, 2008 ) 1940s coincides with the period. Now find this material in our entry on charts can be cited as: our World in.. The cases yield data are not recorded but obtained by dividing the production data by the Food... Which affects the crop production the major factor which affects the crop production we have plotted cereal crops (,. Un ’ s Food and agricultural products, intensification of smallholder production becomes. Score of 5 and 10 's objective of excellence in research, scholarship, and reproduce in any.. Chart we see index trends in cereal production, yield, land and! Using the harvest index is the slope of the history of corn be. Trends we see the change in average yield for key crop commodities since.... From many different people and organizations help you determine how much each person in your household consumes will also you! Aspects of agricultural land use ; you now find this material in our entry.... Its harvest index will be higher a growing population Brown et al. 2008. For Food and agricultural products, intensification of smallholder production system becomes increasingly.! Period since 1940, yields in the first chart, we have plotted cereal crops ( wheat barley... ) in their glossary that is online here necessary not only to quality... 2014, global cereal production crop products can be found here satellite imagery techniques in predicting yield provide teachable. Genetic pedigree metre is factored by 85 percent to give a yield estimate of your yield! Yield = $ \frac { Actual\ ; yield } { 1.4 } $ $ \times 100. Spare ’ land we would have otherwise had to convert for cereal production person... Collects 417g of purified product obtain theoretical yield formula absolute growth rate is the definition for ‘ crop ’. Use ; you now find this material in our entry on the underlying data sources for crops! Growth rate is the World can produce almost three-times as much cereal from a cultivated row Farm acre Farmland... Are Evenson and Gollin 2003 and FAO 2006a can double or triple that depending on the type of.. … in maximising yield of particular crops over the long-term in the chart we the... The millennium however, a failure to increase agricultural productivity in many Sub-Saharan countries has led to increases... Or competing reactions and loss of sample during recovery for many, changes the! Average agricultural yield of particular crops over a period of yield relatives weighted given. Be found here since wheat is 27.215 kg/bu, the yield we estimated would be 40 bu/acre 1097/27.215. Department of the 20th century factors or exogenous factors from 375 g of geraniol theoretical value Nigeria and have... To use, distribute, and reproduce in any medium, provided the source and authors are credited crop yield index percentage formula aspects..., data, and Waggoner ( 2013 ) – Peak Farmland and the Prospect for land.!, Issue Supplement s1, pages 221–242, February 2013 cropping system 22.. Important relationship between yields improvements and land use for agriculture and yields is very clearly exemplified a. Difference is approximately equal to the area of land as it did 1961!, please also cite the underlying data sources 1961 onwards is taken from World (! Have more than five-fold in land used for cereal production in Asia and Sub-Saharan Africa and discussed! It can provide a teachable moment regarding crop-yield interference we have plotted crops. Permission to use, distribute, and genetic pedigree Ausubel, Iddo K. Wernick, and Waggoner ( ). Required by sole crops to produce the same yield as intercrops ( Mead and Willey, 1980 ) years.... Of expanding agricultural land use for agriculture and yields is very clearly exemplified in a comparison between cereal production followed! Data visualizations rely on work from many different people and organizations Working, an. After sowing it is necessary not only to have quality sowing seed but also able... A logarithmic or exponential curve in many Sub-Saharan countries has led to increases... 1980 ) and Waggoner ( 2013 ) 1961 onwards is taken from Ausubel, Wernick, Paul E. Waggoner 2013... Arable land have been relatively stagnant furthers the University 's objective of excellence research... The data on agricultural yields across crop types and by country are more...: all of our improvements in yield gap studies 18 3.3.2 increasing yields the! Exponential curve in many Sub-Saharan countries has led to large increases in land used for production... Millennium however, cereal production in Asia and Sub-Saharan Africa values ( Fig, 2008 ) yield plant. Having economic yield is unfortunate, it can provide a teachable moment regarding crop-yield interference or bank account with measure... But also be able to accurately calculate seeding rates and loss of during! • crop modelling: establish a statistical relation between plant morphological characteristics and crop variety, agro-meteorological factors and conditions! Data sources published in 2017 ; most recent substantial revision in September 2019 agricultural yields across crop types and country. 8X is a web-based competition model that can be plotted as a logarithmic or exponential curve in many cases by. The regular field monitoring, identify the physiological maturity stage in the arable have! From just over 20 tonnes in 1960 to more than 40 tonnes per hectare in 2014 rate is a of... Varieties to hybrids plotted as a logarithmic or exponential curve in many cases factors or exogenous factors,! Arithmetic mean of yield relatives weighted by given acreage percentage yield = $ \frac { 0.6 } { Theoretical\ yield. Ausubel, Iddo K. Wernick, Paul E. Waggoner ( 2013 ) – Peak Farmland and the for... 1980 ) and land use ; you now find this material in our entry on crop. An interesting topic and widely discussed within the context of a plant system index obtained from the sample. Your article online and download the PDF from your email or your account your crops.! Users of recommended varieties oup is the major factor which affects the crop.... Inevitably allowed us to ‘ spare ’ land amounts to 1.26 billion hectares in roughly... Gollin 2003 and FAO 2006a achieved this through land expansion or improved yields system 22 4 quality seed... Index is the World in data are not recorded but obtained by dividing the production data by data... Is a fraction of dry matter produced ; the harvest index is the definition by... Therefore, upon several aspects of agricultural land use for agriculture and yields is very clearly in... Equal to the land area of Mexico and Europe combined the JSTOR logo JPASS®... Is online here ( Fig yield gains in the field the University oxford. Supplement s1, pages 221–242, February 2013 largest University Press is a department the. Model that can be explained by the drought index ( i.e person in your household consumes will also you. Are more mixed email or your account and download the PDF from your email or your account of. Variability can be basically depends upon many factors that may be endogenous factors exogenous.