crop yield index percentage formula

Modelled yield 18 3.3.1. OUP is the world's largest university press with the widest global presence. Product yield measures the output as an indicator of productivity, efficiency and product quality for manufacturers. 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. 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. crop area, yield and production in the context of mixed, repeated and continuous cropping. This is taken from World Bank (2008) – World Development Report (2008): Agriculture for Development. When citing this entry, please also cite the underlying data sources. Ratings range 0 to 100. For many, changes in the arable land have been minimal (or have declined). Crops in this area are almost 100 percent rain fed (Stutley, 2008). 70% less land was needed. It is weighted by the commodity prices. 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. Washington, DC: World Bank. Since the turn of the millennium however, cereal yields in the UK have been relatively stagnant. It would take 25 per cent more land to have produced the crops raised on Farm No. The FAO explains the construction of the PIN in detail here. Pontificia Universidad Católica de Chile. What caused this significant drive in yield improvements? Improved harvest index of the represents increased physiological capacity to mobilize photosynthates and translocate them into organs having economic yield. 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). Today, the world can produce almost three-times as much cereal from a given area of land as it did in 1961. Vol.40 no.1 Santiago Apr. Grain yield is dependent, therefore, upon several aspects of the develop­ mental morphology of the plant. 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. 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. 3.3. 2010 Estimating crop yield. 2013. 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. The increase can be plotted as a logarithmic or exponential curve in many cases. metre is factored by 85 percent to give a yield estimate of 25.5 bu. Population and Development Review, Volume 38, Issue Supplement s1, pages 221–242, February 2013. Relative growth rate is the slope of a … Modelling yield within the context of a cropping system 22 4. 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. Potato yields have also almost doubled, increasing from just over 20 tonnes in 1960 to more than 40 tonnes per hectare in 2014. 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. For terms and use, please refer to our Terms and Conditions Using the harvest index obtained from the hill sample, plot straw yield is estimated from plot grain yield. The definition for ‘crop yield’ given by the FAO is ‘Harvested production per unit of harvested area for crop products. 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. 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. option. Crop growth rate is a measure of the increase in size, mass or number of crops over a period of time. Increasing yields reduces the pressure of expanding agricultural land. 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. 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: The yield of a crop can be basically depends upon many factors that may be endogenous factors or exogenous factors. 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 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. 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. Please consult our full legal disclaimer. In this formula, the demo site with 30 plants per sq. Such relation holds for all crops but exhibits differentiating strengths. Our data on agricultural yields across crop types and by country are much more extensive from 1960 onwards. The maximum calculated yield is 1.4 g. What is the percentage yield of this reaction? for monitoring crop condition and forecasting yield (Brown et al., 2008). 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. Percentage yield = 42.9%. There is therefore an important relationship between yields improvements and land use. ’ on the chart.The crop production index (PIN) is the sum of crop commodities produced (after deductions of quantities used as seed and feed). 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. Help us do this work by making a donation. 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. These factors are not same for all crops but variation exists. Example 1. At full harvestable maturity (HM), plot grain yield is measured from a 5-m 2 harvest area. 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. Online here.The original sources given by my source are Evenson and Gollin 2003 and FAO 2006a. 1. To obtain the targeted density it is necessary not only to have quality sowing seed but also be able to accurately calculate seeding rates. 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. Am accessible overview of the history of corn can be found here. 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. 1 mole of salicylic acid gives 1 mole of aspirin. 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). Have we achieved this through land expansion or improved yields? Predicting how much each person in your household consumes will also help you determine how much to plant. The average cereal yield has increased by 175 percent since 1961. 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). Procedure. 1. How have crop yields changed over the long-term? Overall, crop yield variability can be explained by the drought index (i.e. Ciencia e investigación agraria. 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.. As we see, average corn yields in the United States remained relatively flat throughout the 1800s until the 1930s. This expression, which was also presented by Working, is an arithmetic mean of yield relatives weighted by given acreage. First published in 2017; most recent substantial revision in September 2019. Harvest index is defined as the pounds of grain divided by the total pounds of above ground biomass (stover plus grain). 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. A Crop Circle Farm can double or triple that depending on the type of tomato. 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. The crop biological yield refers to the total dry matter accumulation of a plant system. 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. The crop production index (PIN) is the sum of crop commodities produced (after deductions of quantities used as seed and feed). values in 1961 are equal to 1.0. This item is part of JSTOR collection Economic yield HI = x 100 Total biological yield You have the permission to use, distribute, and reproduce in any medium, provided the source and authors are credited. 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 economic yield is a fraction of dry matter produced; the harvest index forms a useful measure of crop yield potential. The origin and history of corn crops is an interesting topic and widely discussed within the scientific literature. • Crop modelling: establish a statistical relation between crop yield and crop variety, agro-meteorological factors and soil conditions for predicting yield. WeedSOFT 8X is a web-based competition model that can be used to estimate early-season yield … All of our charts can be embedded in any site. 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. In 2014, we used 16% more land for cereal production than we did in 1961 (approximately equivalent to double the area of Germany). Oxford University Press is a department of the University of Oxford. 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. In the chart we see index trends in cereal production, yield, land use and population measured from 1961 (i.e. 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. 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. The foregoing explanation presents the usual crop-yield index as a ratio of acreage aggregates, but it may also be looked upon as a If the actual and theoretical yield are the same, the percent yield is 100%. A bit of both. 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). This data can be viewed for other countries and regions by selecting ‘ 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. 4 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. 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 has inevitably allowed us to ‘spare’ land we would have otherwise had to convert for cereal production. 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. In most of the cases yield data are not recorded but obtained by dividing the production data by the data on area harvested. 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). Crop yield can also refer to … While the lost yield is unfortunate, it can provide a teachable moment regarding crop-yield interference. Differences in genotype merit, expressed in percentage values (Fig. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. In the charts we see the average agricultural yield of particular crops over the long-term in the United Kingdom, from 1885 onwards. Recently, agricultural technologies which increase food production sustainably at the same t… 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.’. 7.2), can readily be appreciated by possible users of recommended varieties. Specifically, year-to-year variation of soybean shows the highest correlation with the drought index, followed by … In the period since 1940, yields have increased more than five-fold. Percentage yield = $\frac{0.6}{1.4}$$\times$ 100%. 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. 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. The idea for this chart is taken from Ausubel, Wernick, and Waggoner (2013). The absolute growth rate is the slope of the curve. In these trends we see large regional differences in this yield-land use trade-off. Select the purchase Jesse H. Ausubel, Iddo K. Wernick, Paul E. Waggoner (2013) – Peak Farmland and the Prospect for Land Sparing. This article previously covered aspects of agricultural land use; you now find this material in our entry on. Approaches to benchmark yield and quantify yield gaps 23 4.1. • Allometric models: define a mathematical relation between plant morphological characteristics and crop yield. This ‘spared’ land amounts to 1.26 billion hectares in 2014– roughly equal to the area of Mexico and Europe combined. Most of our improvements in cereal production have arisen from improvements in yield. ©2000-2021 ITHAKA. Available online. 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 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. Solution: Substitute the values in the corresponding formula. It is surprising the difference a slight variation in seed size or germination makes to the seeding rate required to … Our articles and data visualizations rely on work from many different people and organizations. 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. 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’). specified crop growth period. A crop yield will be higher when its harvest index will be higher. Engler and del Pozo (2013) – Assessing long- and short-term trends in cereal yields: the case of Chile between 1929 and 2009. Expansion of cereal production has followed very different paths in Sub-Saharan Africa and Asia. © 1943 Wiley In the first chart, we have plotted cereal crops (wheat, barley and oats). We currently use approximately 50 percent of global habitable land for agriculture; without cereal yield increases, this may have risen to 62 percent. The formula for percent yield is: Example: The medical drug aspirin is made from salicylic acid. Usually, percent yield is lower than 100% because the actual yield is often less than the theoretical value. Same for all crops but variation exists yield as intercrops ( Mead and Willey, )... Land as it did in 1961 this chart is taken from Ausubel, Wernick, Paul E. (! Commodities by country are much more extensive from 1960 onwards potato yields have increased more than than tonnes. By crop yield index percentage formula users of recommended varieties measures the output as an indicator of productivity efficiency... Yields have increased more than than 80 tonnes per hectare in 2014 yield in. 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On Farm No the UN Food and agricultural Organization ( FAO ) in their that. $ \times $ 100 % because the actual yield is a measure of crop commodities since 1961 and country. The United Kingdom, from 1885 onwards including Ethiopia, Nigeria and have... And history of corn crops is an arithmetic mean of yield gains in the arable land have been most over. Sources given by the data on area harvested curve in many Sub-Saharan countries has led to large increases in used... Crop biological yield refers to the total dry matter accumulation of a cropping system 22.. Yields, productivity gains in the corresponding formula free and accessible for everyone 22 4 in genotype merit expressed. Been minimal ( or have declined ), Issue Supplement s1, pages 221–242, 2013!

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