Eyes in the sky, boots on the ground : assessing satellite- and ground-based approaches to crop yield measurement and analysis in Uganda
Crop yields in smallholder systems are traditionally assessed using farmer-reported information in surveys, occasionally by crop cuts for a sub-section of a farmer's plot, and rarely using full-plot harvests. Accuracy and cost vary dramatically across methods. In parallel, satellite data is improving in terms of spatial, temporal, and spectral resolution needed to discern performance on smallholder plots. This study uses data from a survey experiment in Uganda, and evaluates the accuracy of Sentinel-2 imagery-based, remotely-sensed plot-level maize yields with respect to ground-based measures relying on farmer self-reporting, sub-plot crop cutting (CC), and full-plot crop cutting (FP). Remotely-sensed yields include two versions calibrated to FP and CC yields (calibrated), and an alternative based on crop model simulations, using no ground data (uncalibrated). On the ground, self-reported yields explained less than 1 percent of FP (and CC) yield variability, and while the average difference between CC and FP yields was not significant, CC yields captured one-quarter of FP yield variability. With satellite data, both calibrated and uncalibrated yields captured FP yield variability on pure stand plots similarly well, and both captured half of FP yield variability on pure stand plots above 0.10 hectare. The uncalibrated yields were consistently 1 ton per hectare higher than FP or CC yields, and the satellite-based yields were less well correlated with the ground-based measures on intercropped plots compared with pure stand ones. Importantly, regressions using CC, FP and remotely-sensed yields as dependent variables all produced very similar coefficients for yield response to production factors.
How China Plans to Feed 1.4 Billion Growing Appetites
This is an excerpt. You can read the whole article in National Geographic here.
A 2016 McKinsey & Company study found that nearly three-quarters of Chinese customers worry that the food they eat is harmful to their health. The vast number of small farms makes China’s food system “almost completely unmanageable in terms of food safety,” says Scott Rozelle, an expert on rural China at Stanford University.
The Elusive Goal of Global Food Security
Ending world hunger is a universal goal, yet progress and social awareness of the issue waxes and wanes in the course of broader political and economic developments. The massive famine in China under Chairman Mao’s 1958–62 Great Leap Forward, a succession of severe droughts and associated famines in India in 1965–66, and the political violence that accompanied regime change in Indonesia in 1964–67 left tens of millions of people starving and drew global attention to the threat of food insecurity. What emerged from these events was an international commitment to agricultural technology transfers, water resource development, and foreign assistance – partly in the spirit of humanitarian goodwill and partly in pursuit of long-term geopolitical and economic interests revolving around the Cold War. Whatever the motivation, the outcome over the ensuing decades was more than a doubling of staple cereal yields in Asia, and a steady decline in real (inflation-adjusted) cereal prices.
Despite these gains, a second, quite different, rallying cry for food security resounded in 2007–8 as international grain prices spiked, food riots erupted in numerous cities throughout the developing world, and the global economy headed into a deep recession. Several factors sparked this crisis, but unlike the earlier periods of dire food shortages, the root causes included unwieldy financial markets and escalating demands for food, animal feeds, and fuel (including biofuels) in a globalized economy. This episode prompted new analyses of the connection between global commodity markets and food security, the political-economy foundations of agricultural development, and the differential impacts of food prices on net producers and net consumers. In the five-year period from 2007 to 2012, international cereal prices were highly unstable, varying by as much as 300 percent.
Today, international agricultural markets have settled at relatively low prices, but civil conflicts, extreme climate events, and other natural disasters are blocking the path toward ending hunger. In February 2017, the United Nations declared a famine in South Sudan, as war and economic collapse ravaged the newly independent nation. Although the famine officially ended in mid-2017, food emergencies and severe undernourishment still threaten tens of millions of people in South Sudan, Yemen, Nigeria, Somalia, and Syria, due to a combination of civil conflict, prolonged droughts, and occasional floods. On the surface, it seems incomprehensible that there could be such difficulty in addressing these looming famines at a time when global cereal production and stocks are at historical highs. But the problem is not a matter of food supply; the problem is war.
Improving environmental practices in agricultural supply chains: The role of company-led standards
Food retailers and manufacturers are increasingly committing to address agricultural sustainability issues in their supply chains. In place of using established eco-certifications, many companies define their own supply chain sustainability standards. Scholars remain divided on whether we should expect such company-led programs to affect change. We use a major food retailer as a critical case to evaluate the effectiveness of a company-led supply chain standard in improving environmental farm management practices. We find that the company-led standard increases the adoption of most environmental best management practices among the company's fruit, vegetable and flower growers in South Africa. This result is robust across two identification strategies: a panel analysis of over 950 farm audits and a cross-sectional matching analysis using original survey data. In-depth interviews suggest that the program's unique focus on capacity building through audit visits by highly trained staff, coupled with a close business relationship between the retailer and their growers help to explain the increased effectiveness of the program as compared to other private environmental standards. Contrary to the argument that company-led initiatives are mere window dressing, this study provides a critical example of the positive role private governance mechanisms can play in improving environmental farm management practices globally.
Feeding Africa and the World in the 21st Century
Food security experts identify government support, policy implementation, private sector engagement and investment in smallholder farmers as keys to Africa’s agricultural future.
Food security experts from the Alliance for a Green Revolution in Africa (AGRA) gathered to discuss transforming food production in Africa at Stanford on Nov. 29. The symposium, hosted by the Center on Food Security and the Environment (FSE) examined the challenges, strategies, and possible solutions for catalyzing and sustaining an inclusive agriculture transformation in Africa.
Moderator Ertharin Cousin, FSE visiting fellow and previous World Food Programme director with more than 25 years of experience on hunger, food, and resilience strategies, launched the panel by outlining Africa’s plight. “Today some 100 million of the farmers across Sub-Saharan Africa farm less than 2 hectares of land. Some 80 percent of those living in rural areas are poor. More than 30 percent of the rural population is chronically hungry and 35 percent of the under-five-year-olds are stunted. By 2050, the bulk of the world's population growth will take place on the continent. In fact, some project that 1.3 billion will be added to the continent, and Nigeria’s [population] will grow larger than the size of the United States between now and 2050,” Cousin said
.
While Africa continues to experience the highest occurrence of food insecurity worldwide, the continent also contains over 60 percent of the worlds uncultivated but fertile land. AGRA formed in 2006 to fulfill the vision that Africa can feed itself and the world. Panelists included Agnes Kalibata, AGRA President and former Minister of Agriculture and Animal Resources of Rwanda; Kanayo F. Nwanze, AGRA board member and immediate past president of the International Fund for Agricultural Development; Usha Barwale Zehr, AGRA board member and Director and Chief Technology Officer of Maharashtra Hybrid Seeds Company Private Limited; and Rajiv Shah, AGRA board member, Rockefeller Foundation President and former Administer of USAID.
Kanayo F. Nwanze stressed the importance of agricultural transformation for Africa’s future. “No country in the world ever transformed itself without going through an agrarian change. No country. Europe, 17th; Japan, 18th century; 19th century was the US, your country; China, 20th century. Why should they be different from Africa? So, first and foremost, we have to have total agricultural transformation,” Nwanze said.
AGRA president, Agnes Kalibata, also spoke to the need for policy implementation and government support in helping drive change. “AGRA as an institution can only do so much. But these governments have the potential and the capacity to reach every corner of their countries. The problem is they are challenged by capacity to do that, by capacity to design proper programs, and by capacity to implement these programs,” Kalibata said.
Expanding on governments' ability to impact and drive change, Usha Barwale Zehr highlighted Asia’s success, specifically with strategic partnerships. “…we've done a lot of talking about public/private partnership. Not so much on the ground on implementing it in a manner, which happened in Asia, for instance, where there was policy, and, most importantly, government will. The government was willing to do whatever it took to make sure that agriculture was transformed at the end of it,” Zehr said.
Beyond government and policy support the panelists also addressed the need for innovation and access to seed technologies. “Why is it that the African farmer and the Indian farmer should not have access to what the American farmer has access to today and reaps benefit from it? …So it's the hybrids, the varieties, the GM technology. Tomorrow it'll be the gene-edited products. And after that we will talk about the satellite-based imaging data that we will use for developing drought-tolerant crops for that very, very small micro environment that existed in the one district in Nigeria,” Zehr said.
"By 2050, who is going to feed Africa? … It's the youth of today. But they're not going to be using the same technologies that exist today. Just think of what IT can do, aggregation, organization of farmer's groups. So, the elements are there. I see the agriculture of tomorrow meeting the challenge – for Africa meeting that challenge is Africa being at the forefront of feeding the world. Africa has to be able to feed itself first. And we have all the opportunities there,” Nwanze said.
This is the first installment of the Global Food Security Symposium series hosted by Stanford University's Center on Food Security and the Environment and generously supported by Zach Nelson and Elizabeth Horn. FSE is a joint initiative of the Stanford Woods Institute for the Environment and the Freeman Spogli Institute for International Studies.
Revolutionizing Food Security in Africa
Stanford’s Center on Food Security and the Environment launches new symposium series focused on global food security with panel exploring Africa’s agricultural potential.
Food security experts from the Alliance for a Green Revolution in Africa (AGRA) will gather at Stanford for meetings and a symposium on transforming food production on that continent. R.S.V.P by Nov. 28 for Symposium: Can Africa rise to the challenge of feeding itself in the 21st century? | Nov. 29
Organized by the Center on Food Security and the Environment (FSE), the Nov. 29 symposium is the first in the center’s new Global Food Security Symposium series. Panel members include visiting AGRA board members, who will examine the challenges, strategies, and possible solutions for catalyzing and sustaining an inclusive agriculture transformation in Africa. This symposium marks the third series established by FSE convening thought leaders addressing global food security issues.
Afflicted by conflict, political upheaval, and extreme weather patterns Africa continues to experience the highest occurrence of food insecurity. However, with over 60 percent of the worlds uncultivated but fertile land, there is significant room for improvement. AGRA formed in 2006 to fulfill the vision that Africa can feed itself and the world. As an alliance led by Africans with roots in farming communities across the continent, they work to understand the unique needs of farmers and offer sustainable solutions designed to boost production.
In a region with 27.4 percent of the population currently experiencing food insecurity, creating a sustainable agricultural revolution remains a key solution to improving food security across the area. Moderated by Ertharin Cousin, previous World Food Programme director, with 25 years of experience on hunger, food, and resilience strategies, the panel will explore how an agricultural transformation in Africa can sustain a growing population, relieve hunger, generate jobs, improve social cohesion, and create global exports.
Panel members include:
Ertharin Cousin (moderator), Payne Distinguished Lecturer at the Freeman Spogli Institute for International Studies and Visiting Fellow at the Center on Food Security and the Environment, former US Ambassador to the UN Agencies for Food and Agriculture in Rome.
Agnes Kalibata, the President of AGRA and former Minister of Agriculture and Animal Resources of Rwanda.
Kanayo F. Nwanze, the immediate past president of the International Fund for Agricultural Development (IFAD), winner of the Africa Food Prize in 2016, AGRA board member.
Rajiv Shah, Rockefeller Foundation President, former Administer of USAID (2010-15) where he led bipartisan reform and expansion of US efforts combating global food insecurity. During his previous work at the Gates Foundation he helped launched AGRA.
Usha Barwale Zehr, Director and Chief Technology Officer at Maharashtra – one of India’s largest and most successful multinational seed companies – and AGRA board member.
This is the first installment of the Global Food Security Symposium series hosted by Stanford University's Center on Food Security and the Environment and generously supported by Zach Nelson and Elizabeth Horn. FSE is a joint initiative of the Stanford Woods Institute for the Environment and the Freeman Spogli Institute for International Studies.
Can Africa rise to the challenge of feeding itself in the 21st century?
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Using satellite data to identify the causes of and potential solutions for yield gaps in India's Wheat Belt
Food security will be increasingly challenged by climate change, natural resource degradation, and population growth. Wheat yields, in particular, have already stagnated in many regions and will be further affected by warming temperatures. Despite these challenges, wheat yields can be increased by improving management practices in regions with existing yield gaps. To identify the magnitude and causes of current yield gaps in India, one of the largest wheat producers globally, we produced 30 meter resolution yield maps from 2001 to 2015 across the Indo-Gangetic Plains (IGP), the nation's main wheat belt. Yield maps were derived using a new method that translates satellite vegetation indices to yield estimates using crop model simulations, bypassing the need for ground calibration data. This is one of the first attempts to apply this method to a smallholder agriculture system, where ground calibration data are rarely available. We find that yields can be increased by 11% on average and up to 32% in the eastern IGP by improving management to current best practices within a given district. Additionally, if current best practices from the highest-yielding state of Punjab are implemented in the eastern IGP, yields could increase by almost 110%. Considering the factors that most influence yields, later sow dates and warmer temperatures are most associated with low yields across the IGP. This suggests that strategies to reduce the negative effects of heat stress, like earlier sowing and planting heat-tolerant wheat varieties, are critical to increasing wheat yields in this globally-important agricultural region.