Large Yield Gaps Research Articles

Analyzing the rainfed wheat yield gap in Northwest Iran

Wheat is one of the major crops in Iran, covering more than 36% of the total croplands and more than 70% of rainfed farmlands. However, the trend of crop yield in the past decades does not show promising performance and the average yield of rainfed wheat in Iran is as low as 1250 ​kg ​ha−1. Therefore, quantifying the rainfed wheat yield gap, and determining its causes and importance could help wheat self-sufficiency in Iran. Boundary line analysis (BLA) and regression tree (RT) models were employed to analyze the yield gap and find out the influencing factors. For this purpose, an on-farm survey was conducted in 210 rainfed winter wheat fields in East Azerbaijan province during the 2020–21 cropping season. Data were collected from local experts and farmers concerning crop yield and related management practices. Actual farmers’ yields were 1095 ​kg ​ha−1. BLA showed a significant yield gap ranging from 1755 to 2186 ​kg ​ha−1 (61.5–66.6% of attainable yield) and determined the attainable yield of 3072 ​kg ​ha−1. The BLA indicated that, among the quantitative independent variables, nitrogen fertilizer and planting density management were the important managerial practices responsible for the yield gaps. Additionally, the pronounced differences in crop yield across various rotation systems and varieties highlight their critical role in realizing crop attainable yield as the qualitative independent variables. By the regression tree (RT) model, the yield gap was determined about 65%. Crop rotation, crop variety, and sowing date were determined as key factors influencing the rainfed wheat yield gap. Findings showed that the combination of BLA and RT methods can be used effectively to quantify the crop yield gap and its influencing factors. Regarding the large yield gap, there is a good opportunity to obtain higher yields by optimizing managerial practices/inputs.

Beyond yield: Unveiling farmer perceptions and needs regarding weed management in Bangladesh.

More than 3.5 billion people depend on rice for more than 20% of their daily calories. Globally, Bangladesh is the third largest rice producer. With 171 million people, Bangladesh is also among the top consumers. Local rice production not only affects the country's food security but also influences the global rice trade. A large yield gap has been reported due to weeds. Traditional hand weeding is very costly because of labor shortages resulting from industrialization. Limited data showed a higher yield and profits when using herbicides. However, quantitative data on various aspects of weed management and associated issues representing the country's variable rice ecosystem, which is characterized by 30 agroecological zones, are lacking. We collected data on weed management practices from 865 farmers and 69 agrochemical shops covering all 30 agro-ecological zones (AEZs) through a structured survey. We observed a significant regional variation among various parameters. Approximately 82% of farmers use herbicides, and few rely solely on either manual weeding or herbicides. Pre-emergence herbicides are the predominant. Application procedures are almost the same across the country. Although 40% of farmers had secondary and higher-level education, most depend upon local sellers' suggestions rather than reading the product label regarding the dose. Few farmers consider herbicides hazardous, and respondents rarely perceive any environmental impact. Pyrazosulfuron ethyl (35%) and acetochlor-containing bensulfuron methyl (27%) are the most-used chemical species. Approximately 45% of farmers observed that herbicides suppress early seedling growth. Additional fertilizer is required to compensate for this. Multiple weed species that are difficult to control through presently used herbicides were noted in all AEZs. Around 64% of farmers observed that herbicide application contributes to higher yields as a function of timely weeding. Cost comparisons showed that high labor prices will make rice cropping unprofitable in most parts of the country if herbicides are eliminated. Clear adverse effects of pre-emergence herbicides on early crop growth implied the potential benefits of broad-spectrum herbicide-tolerant genetically engineered (GE) rice to sustain the country's food security. Additionally, such GE rice could incentivize the adoption of alternate wet and dry irrigation methods, leading to water and cost savings.

Analysis of socioeconomic characteristics on coffee yield gap among smallholder farmers in Nyeri Central sub-county, Kenya

Kenya’s coffee production has been declining over the years leading to decreased yields and making it hard for farmers to benefit from the sector. This has resulted in a considerable yield difference, with actual farmer yields far below the potential yields of station trials. This large yield gap reveals an enormous potential for yield improvement in coffee production. However, the large yield gap may be attributed to several factors, yet there is limited quantitative information on site-specific factors and the yield gap attributed to the factors. This study informs the knowledge gap by analysing the effect of socioeconomic characteristics on the coffee yield gap of smallholder farmers in Nyeri Central sub-county, Nyeri County. A cross-sectional research design was used, and a sample of 175 smallholder coffee farmers was drawn using the systematic random sampling technique. Data on socioeconomic characteristics was analysed using SPSS version 29, and their effect on the coffee yield gap was determined using a fractional logit regression model in STATA version 17. The findings noted that the yield gap index per variety was 88.54% for Ruiru 11, 93.78% for Batian, and 95.68% for SL 28. The model parameters indicated that the gender of the household head, schooling years, household size, and labour were negative but significant at p<0.05. This study concluded that smallholder coffee farmers were producing below their potential, as depicted by the large yield gap estimate. Therefore, feasible actions are required to close the existing yield gap, increase coffee yields, and enhance household food security.

Crop Nutrition and Soil Fertility Management in Organic Potato Production Systems

Organic farming is a comprehensive production management system that fosters and improves the health of agroecosystems, encompassing biodiversity, biological cycles, and soil biological activity. The potato (Solanum tuberosum L.) is a crucial crop in organic farming systems, standing out as one of the most highly demanded organic products on the market. Among all crops, with potatoes, there is a very large yield gap between organic and conventional systems, attributable mainly to its intensive nutrient demands. The present review, considering the most relevant scientific literature worldwide, discusses the contemporary state of knowledge on crop nutrition and soil fertility management in organic potato crop production, analyzing the effects of animal manures, green manures, organic amendments, and biostimulants on organic potato tuber yield and quality. Overall, the main findings show a particular combination is needed to effectively maintain good soil fertility, satisfy the nutritional needs of the crop, and overcome the difference in potato yield between organic and conventional farming methods while meeting consumer demand. This combination entails using an animal manure or leguminous green manure with an organic soil amendment, and even better with a biofertilizer, such as a mycorrhizae-fungus-based one. It also emerged that more targeted studies are needed to select appropriate cultivars for organic potato farming systems to optimize this environmentally friendly production method.

Chemical constraints are the major limiting factor of root deepening in southern Brazil soils

Large soybean yield gaps are related to irregular rainfall patterns in several rainfed soybean crop regions, such as southern Brazil. More efficient rainwater use can be achieved in these regions through deeper roots. Therefore, assessing the status of soybean rooting and soil-related factors that drive root growth in soybean fields is mandatory for making management decisions that minimize the yield gap. To this end, we conducted a survey in 10 fields in the state of Rio Grande do Sul (RS), Brazil, during the 2021/22 season. Undisturbed soil blocks and cores and disturbed soil samples were collected in trenches up to approximately 80 cm deep when the soybean was at the R5 stage. The roots washed from the soil blocks were scanned to determine the relative root length density (RRLD), whereas the soil cores and disturbed samples were used for physical and chemical analyses. Hierarchical cluster analysis based on the RRLD was performed to group fields according to their similarities in root distribution and soil-related factors. Soybean rooting in RS fields is quite shallow, with >72% of the total RRLD in all fields located within the 0–20 cm layer and <15% deeper than 40 cm in most fields. Chemical constraints, such as high gradient of acidity-related variables along soil profile and low concentration of nutrients below 20 cm depth, limited soybean root deepening in 50% of the fields, while physical constraints were predominant in 30% of the fields. Thus, management strategies for reducing soybean yield gap by increasing rooting depth in fields of RS need to focus on improving subsurface chemical conditions for root growth.

Enhancing Summer Soybean Yield through Evaluation of Herbicidal Weed Management Options

The farmers of Gujarat have turned to soybean cultivation as soybean demand is increasing promisingly. Improper weed management is one of the reasons for the large yield gap between the potential and the actual yield of soybean harvested by the farmers. So, the selection of different herbicides in soybean is necessary for effective management of complex weed flora. An experiment was plotted with an aim of enhancing summer soybean yield through evaluation of herbicidal weed management options on medium black calcareous soil at Junagadh Agricultural University, Junagadh during summer season of 2021. The experiment comprised 12 treatments that were arranged in randomized block design with 3 replications. The outcomes of the results revealed that following to weed-free treatment, pre-mix pendimethalin + imazethapyr 750+50 g/ha as pre-emergence (PE) fb hand-weeding (HW) &amp; inter-culturing (IC) at 30 days after sowing (DAS), HW at 15 DAS fb pre-mix propaquizafop + imazethapyr 50+75 g/ha as post-emergence (PoE) at 30 DAS, HW at 15 DAS fb pre-mix fluazifop-p-butyl + fomesafen 125+125 g/ha (PoE) at 30 DAS and pre-mix pendimethalin + imazethapyr 750+50 g/ha (PE) fb pre-mix fluazifop-p-butyl + fomesafen 125+125 g/ha (PoE) at 30 DAS enhanced growth parameters viz., plant height, branches per plant; yield attributes i.e., number of pods per plant and ultimately lead to greater seed yield and stover yield. These herbicidal weed management options also reduced population in addition to dry matter of weeds and had less reduction in yield due to better control of weeds, less crop-weed competition and higher weed control efficiency.

Gaps between Rice Actual and Potential Yields Based on the VPM and GAEZ Models in Heilongjiang Province, China

Heilongjiang Province is a significant region for grain production and serves as a crucial commodity grain production base in China. In recent years, due to the threat of declining cropland quality and quantity, coupled with the increasingly prominent demand for grain, there is an urgent need to enhance rice yields in Heilongjiang Province. It is imperative to accurately identify the gaps between actual and potential grain yields and effectively implement yield-enhancing measures in regions with significant yield gaps. This study aimed to determine the rice reproductive periods of Heilongjiang Province for 2000, 2010, and 2020, estimate the rice actual yields using the Vegetation Photosynthesis Model (VPM), simulate the rice potential yields based on the Global Agro-Ecological Zones (GAEZ) Model, and then identify the rice yield gaps at the pixel level by calculating the rice absolute yield gap (AYG) and relative yield gap (RYG). Additionally, yield-enhancing measures were proposed for regions with significant yield gaps. The results were as follows. (1) The rice reproductive periods of Heilongjiang Province for 2000, 2010, and 2020 were determined as days 153~249, days 145~249, and days 137~249. (2) The mean rice actual yield and potential yields decreased by 1222 and 5941 kg ha−1 during the 2000–2020 period, respectively, and the total actual and potential production increased by 3.75 and 1.70 million tons in Heilongjiang Province, respectively. (3) The rice AYG and RYG in the Sanjiang Plain region, such as Jixi City, Hegang City, and Jiamusi City were relatively large compared to other regions for the three years, and the rice yield gaps continued to decrease during the 2000–2020 period. (4) With regard to the Sanjiang Plain region with a large rice yield gap, this study proposes measures to narrow the rice yield gap by establishing ecological protection forests on cropland, transforming low- and middle-yielding fields, increasing agricultural science and technology inputs, selecting better rice cultivars, etc., which are important for ensuring food security.

Using microsatellite data to estimate the persistence of field-level yield gaps and their drivers in smallholder systems

One way to meet growing food demand is to increase yields in regions that have large yield gaps, including smallholder systems. To do this, it is important to quantify yield gaps, their persistence, and their drivers at large spatio-temporal scales. Here we use microsatellite data to map field-level yields from 2014 to 2018 in Bihar, India and use these data to assess the magnitude, persistence, and drivers of yield gaps at the landscape scale. We find that overall yield gaps are large (33% of mean yields), but only 17% of yields are persistent across time. We find that sowing date, plot area, and weather are the factors that most explain variation in yield gaps across our study region, with earlier sowing associated with significantly higher yield values. Simulations suggest that if all farmers were able to adopt ideal management strategies, including earlier sowing and more irrigation use, yield gaps could be closed by up to 42%. These results highlight the ability of micro-satellite data to understand yield gaps and their drivers, and can be used to help identify ways to increase production in smallholder systems across the globe.

Agronomy explains large yield gaps in smallholder oil palm fields

CONTEXTPalm oil production is a major source of income for millions of smallholders in Indonesia. However, actual yield remains low in relation to the attainable yield. While emphasis has been given to planting material as a factor explaining low yield in smallholder fields, the role of agronomic management has received less attention. OBJECTIVEWe assessed the role of agronomic management in explaining low oil palm productivity in independent smallholder fields in Indonesia. METHODSWe quantified yield gaps and their causes using data on fresh fruit bunch (FFB) yield and management practices collected over two years across 977 fields. The yield gap was estimated for each field as the difference between actual and attainable yield. The latter was estimated using a crop model, local weather and field-specific soil and palm age. Statistical techniques were used to identify factors explaining yield gaps. RESULTS AND CONCLUSIONSAverage yield represented 42% of the attainable yield, with largest yield gaps occurring in young plantations. Our analyses identified agronomic practices explaining yield gaps, including nutrient management, harvest interval, weed control, and pruning. Improved agronomic management can help smallholders increase yield and profit on existing plantations. SIGNIFICANCEThere is an opportunity to produce more palm oil on current plantation area via better agronomy, generating a positive economic impact at local to national levels, while reducing pressure to clear new land for cultivation. Research & extension programs should be re-oriented to give more emphasis to agronomic management.

Evaluating Yield Gap and Yield Improvement Potential in the Dairy Sector of Pakistan

A survey data of 600 dairy farms obtained from the largest dairy cluster in Pakistan’s Punjab was used to provide new evidence on the yield gap and yield improvement potential of dairy farms producing milk and meat. The yield gap was estimated by the frontier-based input distance function analysis. The results indicated that a large yield gap exists in the sample where an average dairy farm has a yield improvement potential of 55 percent. By closing the gap, an average dairy farm can increase yearly production of fat-corrected milk (FCM) by 120,036 kg and non-milking herd for meat by 25 heads. The evidence also shows that small farms (&lt; 25 herd-size) are technically more efficient than those of medium (26 ≤ herd-size ≤ 50) and large farms (&gt; 50 herd-size). The study finds clear evidence of an efficiency boost for keeping a higher share of non-milking to milking herd, a greater proportion of exotic cows to local breeds, and a higher farm-gate price of milk, which can all trigger efficiency gains. Policymakers hence have room to provide adequate intervention strategies that can help in enhancing efficiency.

A Self-Crystallized Nanofibrous Ni-GDC Anode by Magnetron Sputtering for Low-Temperature Solid Oxide Fuel Cells.

The optimum composition ratio of the anode cermet (Ni-GDC) for solid oxide fuel cells (SOFCs) varies because the electron-collecting mechanism is different depending on its applications. A Co-sputtering method facilitates ratio control with sputtering power adjustment. However, there is a practical issue with fabricating anode cermet with various ratios attributed to the large sputtering yield gap of the metal target, Ni, and the ceramic target, gadolinia-doped ceria (GDC). Therefore, in this study, a Gd-Ce metal alloy was applied instead of GDC to match the sputtering rate with that of Ni, which enables a wide ratio range achievement. A thin film of Gd-Ce oxidized after deposition and successfully transformed to crystallized GDC under a SOFC operation environment. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) confirmed its crystallinity, and the film deposited with various power ratios was sputtered on the ScSZ electrolyte pellet to clarify the optimum Ni-GDC ratio for thin-film SOFCs. Last, the Ni-GDC was applied to anodized aluminum oxide (AAO)-supported SOFCs to maximize the performance. The performance change according to the thickness of Ni-GDC was identified, and the best performance among them was 638 mW/cm2 at 500 °C.

Narrowing maize yield gaps across smallholder farming systems in Zambia: what interventions, where, and for whom?

Maize production in Zambia must increase with a view towards improved food security and reduced food imports whilst avoiding cropland expansion. To achieve this, it is important to understand the causes behind the large maize yield gaps observed in smallholder farming systems across the country. This is the first study providing a yield gap decomposition for maize in Zambia, and combining it with farm typology delineation, to identify the key limiting factors to maize yield gaps across the diversity of farms in the country. The analysis builds upon a nationally representative household survey covering three growing seasons and crop model simulations to benchmark on-farm maize yields and N application rates. Three farm types were delineated, including households for which maize is a marginal crop, households who are net buyers of maize, and households who are market-oriented maize producers. Yield gap closure was about 20% of the water-limited yield, corresponding to an actual yield of 2.4 t ha− 1. Market-oriented maize farms yielded slightly more than the other farm types, yet the drivers of yield variability were largely consistent across farm types. The large yield gap was mostly attributed to the technology yield gap indicating that more efficient production methods are needed to raise maize yields beyond the levels observed in highest yielding fields. Yet, narrowing efficiency and resource yield gaps through improved crop management (i.e., sowing time, plant population, fertilizer inputs, and weed control) could more than double current yields. Creating a conducive environment to increase maize production should focus on the dissemination of technologies that conserve soil moisture in semi-arid areas and improve soil health in humid areas. Recommendations of sustainable intensification practices need to consider profitability, risk, and other non-information constraints to improved crop management and must be geographically targeted to the diversity of farming systems across the country.

New paradigm for transforming Indian agriculture to climate-resilient and sustainable agriculture is a must

Indian agriculture is the backbone of India’s food, nutrition, and income security as well as sustainable growth. Indian agriculture is unique with 20 agro-eco regions, and 80 agro-eco sub-regions growing more than 100 crops in 1000,000 villages by 145 million farm-holders. India moved from ship to mouth situation in the late 1960s to food self-sufficiency and has become Atmanirbhar and an exporter of food by producing 316.06 million tonnes in 2020-2021. However, rural India needs urgent attention as there is a great divide between the urban and rural family incomes, and the primary sector’s contribution to national GDP is hovering around 17-18% although the Indian economy is largely agrarian with 950 million rural population driving the economy. However, there is a large untapped potential in Indian agriculture to become the growth engine for the sustainable development of India as large yield gaps are existing. However, the challenges of growing water scarcity, increasing land degradation, growing population, urbanization, and most importantly impacts of climate change. Due to climate change with increasing temperatures, aridity is increasing in the country, and rainfall variability with a reduced number of rainy days and increasing intensity in different parts is a major concern. There is an urgent need to develop and adopt large-scale climate resilient management practices at a local level through empowering the small farm-holders with strengthened science of delivery using new science tools such as remote sensing (RS), global information system (GIS), internet of things (IoT), information technology (IT), artificial intelligence (AI), machine learning (ML), etc. Business as usual will not work and a new paradigm through building partnerships, enhancing collective action, market-led agro-eco region-based diversification and scaling-up through the empowerment of small farm-holders using new science tools is proposed. The government of India’s action plan with 11 national missions is in place and all stakeholders need to contribute by enabling policies and sincere implementation for building resilience against the impacts of climate change.

Global Wheat Production and Threats to Supply Chains in a Volatile Climate Change and Energy Crisis

As climate change and energy crises increase, NPK (nitrogen, phosphorus and potassium) fertilizer supply chains become more volatile. Globally, the Russian attack on Ukraine has caused the cost of gas to rise and fertilizer supplies to decline. This aggression may worsen the energy and wheat resource crisis in global supply chains. As a result of the escalation of hostilities, natural gas, oil, and coal prices have rapidly increased. In the years preceding the conflict, the agricultural sector had already begun to suffer, caused by unprecedented increases in the prices of natural gas and raw materials for the production of fertilizers stemming from Russian manipulation, especially in the gas market. Prior to the growing season, farmers were still unable to afford fertilizer prices. This situation will be exacerbated by the war. We can conclude from our results that European countries and the United States have high wheat production potential. Developed countries have significant nitrogen, phosphorus, and potassium fertilizer resources. Ukraine has a large yield gap, ranging between 4.5 and 7 Mg/ha. Wheat supply crises can be caused by tense geopolitical affairs, including military aggression and economic embargoes. Based on this, we recommend that decision-makers focus on crop quality to increase the country’s own production.

Analysis of Gaps Yield and Resource use Efficiency of Cold-Region Japonica Rice

Rice is the primary staple food for more than 50% of the world’s population. Narrowing the gap between the maximum potential food crop yield and actual yield is critical for improving the current yield, resource use efficiency, and global food security. Here, we examined the fertilizer use efficiency (FUE), radiation use efficiency (RUE), and temperature production efficiency (TPE) of four management treatments (super high yield [SH], high yield and high efficiency [HH], farmer level [FP], and basic production level [CK]). SH and HH treatments significantly reduced the yield gap by 22.4 and 9.5%, respectively. The large yield gap between HH and FP was mainly attributed to high specific leaf weight at the jointing stage (7.5–7.7 mg·cm−2), and the high leaf area maintained during tillering–jointing stages (35.4–37.6 m2·m−2·per day). Compared with FP, HH increased the specific leaf weight in the heading stage (8.2–8.4 mg·cm−2), relative crop growth rate, net assimilation rate (NAR), and mean leaf area index (> 2.6). Moreover, compared with FP, HH significantly increased partial factor productivity (PFP) of nitrogen, FUE, TPE, and RUE owing to greater yield and NAR after the full heading stage. Although the HH yield was 93.32% that of SH, HH increased PFP of fertilizer (12.5%), fertilizer nitrogen (9.07%), and fertilizer K2O (36.34%), and required 26% less fertilizer than SH. The findings of this study could facilitate high-efficiency rice production and bridging of yield gaps.

Chinese expert consensus on early diagnosis and treatment of esophageal cancer

Although the incidence rate of esophageal cancer in China is on the decline, China is still a high-incidence country of esophageal cancer with great regional variation. In recent years, the five-year survival of esophageal cancer in China has improved significantly. However, due to the absence of typical symptoms in early stage, there still exists a large esophageal cancer diagnostic yield gap between China and developed countries. At present, there are no international guidelines defining the target population for esophageal squamous cell carcinoma (ESCC) screening. Exploring and implementing effective esophageal cancer screening together with early diagnosis and early treatment are the keys to reducing the mortality and improving the survival rate and life quality. Endoscopic therapies, such as endoscopic submucosal dissection (ESD), endoscopic mucosal resection (EMR), and radiofrequency ablation (RFA), are used to treat early-stage esophageal cancer. If the tumor invasion is deep or lymph node metastasis is suspected, surgery is needed, meanwhile radiation therapy could also be an optional treatment. Regular follow-up and surveillance are required for any strategy above to deal with relapse and metachronous primary cancers. The Early Diagnosis and Treatment Group of the Chinese Medical Association Oncology Branch has reached an expert consensus on screening and diagnostic protocols for esophageal cancer, on endoscopic and surgical treatment of early esophageal cancer and precancerous lesions, as well as on postoperative monitoring and adjuvant therapy. This consensus follows the evidence-based medicine at both domestic and international levels, combines the current clinical practice and application experience in the treatment of esophageal cancer in China, is based on a multidisciplinary treatment model, and can be used as a reference for clinicians.

Towards sustainable productivity enhancement of rice-based farming systems in sub-Saharan Africa

In the past 50 years, rice has become an important crop for food security in sub-Saharan Africa. However, rice yields remain relatively low, and large yield gaps exist. This Special Issue brings together agronomy research on rice-based farming systems in sub-Saharan Africa and addresses three main, overarching questions: (1) what has been achieved in the past decades in terms of rice agronomy in sub-Saharan Africa, (2) what is the state-of-the-art regarding development of technologies and (3) what will be likely or required future directions? The broad topics included in this Special Issue are (1) yield trends and yield gap analyses, (2) soil & nutrient, water, weed and integrated crop management practices, (3) cropping systems, (4) genetic improvements, (5) crop simulation modeling, and (6) assessment of farmers’ rice cultivation practices and the sustainability of these practices. The papers cover different sub-regions, from the Sahel to the highlands of Madagascar and three major rice growing environments (irrigated lowlands, rainfed lowlands, and rainfed uplands). In this paper we describe the major challenges in the rice production sector in sub-Saharan Africa and historical efforts on agronomy research, and we provide a short introduction and discussion on the papers presented in this Special Issue. This Special Issue arrives at six main recommendations. 1. There is a need to increase research and development efforts focusing on rainfed rice-based systems. 2. More attention needs to be paid to research on the farming system or landscape level, aimed at development of integrated cropping and farming systems and integrated agronomic solutions. 3. Current and future agronomic rice research should thematically center around sustainability, including judicious natural resources management, climate change adaptation and mitigation, and conservation of biodiversity and environments. 4. To operationalize this, sustainability performance indicators need to be developed and used. 5. There is broad consensus regarding the need for more labor-saving technologies, including mechanization options, provided these do not increase the ecological footprint of production systems. 6. Future rice agronomy research work should be interdisciplinary and transdisciplinary, to better address the myriad of challenges of smallholder farmers in Africa. Papers presented in this Special Issue should inform on the state-of-the art in rice agronomy in SSA, and on ways to sustainably enhance rice production and self-sufficiency in this region.

Productivity Potential and Yield gap estimation of pulse crops in Ethiopian Agriculture

This study aims to provide a detailed analysis of the pulse crops yield gaps for extra grain in production in Ethiopia. The study covers the period 2006/07-2020/21. Central Statistical Agency of Ethiopia (CSA) Agricultural Sample Survey (AgSS) and crop variety register issue of the Ministry of Agriculture (MoA) data were used for the analysis. The data was analyzed using descriptive statistics and econometric analysis. The descriptive analysis provides quantitative estimates of yield gaps to measure and compare yield potentials and actual yields. Pooled Mean-Group (PMG) model was used to analyze the impact of yield and area on production. After cereals, the second most important crop group (in terms of acreage) is pulses. The area cultivated of pulses is grown by 29.6% between 2006/07-2020/21, which is a faster growth compared to the oil crops area (-3.8%). Pulse production has grown significantly in the country over the past 16 years, rising from around 12.7 million quintals in 2006/07 to 32 million quintals in 2020/21 with growth rate of 151.7%. The production has more than doubled, because of a 64.3% increase in area under the crop and a 35.7% increase in yield during the same period. The average pulses yield level is very low (1.4 tons/ha) as compared to that of the estimated average potential (2.0 tons/ha) in the country for the studied crops. For the analyzed period, results shows 0.2 qt/ha, 8.5 qt/ha, 9.1 qt/ha, 5.7 qt/ha, 2.0 qt/ha, 16.7 qt/ha, and 7.9 qt/ha for chick-peas, faba beans, field peas, gibto, haricot beans, mung bean and, lentils yield gap existed when the national average yield was compared with that of the released cultivars potential under farmer management, respectively for the analyzed period 2020/21. Our findings suggest that if farmers had closed yield gap, Ethiopia could have potential grain surplus of chick-peas, faba beans, field peas, gibto, haricot beans, mung bean, and lentils production by a respective of 4, 427, 200, 8, 61, 67, and 80 thousand Mt, without expanding cropland area. Based on the Pooled Mean-Group (PMG) model result, if cultivated area and yield of crops are increased by 1% then the production growth will be increased by 1% and by 0.99% in the long run respectively. Overall, this study reveals that there are large yield gaps and that substantial benefit for food production are possible through closing these gaps, without the need for new technology and expanding cropland area.

Closing rice yield gaps in Africa requires integration of good agricultural practices

Despite decades of international research and development efforts focusing on increased rice production in Africa, there is large yield gap, and the local production still needs to be complemented by rice imports to meet consumption demands. This paper aims to provide an overview of published research findings on rice yield gaps and the effects of ‘good agricultural practices’ (GAPs) on rice yield and nutrient use efficiency. The majority of previous studies were from irrigated lowlands, and quantified rice yield gaps as farmer-based (difference between ‘actual yield’ and ‘best farmers’ yield’) and model-based yield gaps (difference between ‘actual yield’ and ‘potential yield for irrigated and water-limited potential yield for rainfed rice’). The mean farmer- and model-based yield gaps were 3.1 and 5.0 t ha–1 for irrigated lowland (IL); 3.1 and 7.7 t ha–1 for rainfed lowland (RL); 2.0 and 6.0 t ha–1 for rainfed upland (RU), respectively in Africa. An analysis of studies from literature on GAPs in Africa revealed that most studies (64 %) were from IL and a wide range of yield increases following individual components of GAPs across environments. A median yield increase of 1.0 t ha–1 was achieved with improved water conservation practices in IL, whereas improved weed management increased yields by 0.7 t ha–1, mainly in IL compared to farmers’ practices. Application of inorganic fertilizers and/or organic amendments increased the yield by 0.8–1.2 t ha–1 across the environments. Integration of GAPs increased the median yield by 2.1 and 1.5 t ha–1 in IL and RL, respectively. The calculated agronomic efficiency of N, P and K from fertilizer experiments were within the desirable levels mainly in the IL and RL environments and comparable to the values from similar environments in Asia. For instance, the agronomic efficiency of N was 21, 13 and 12 kg kg–1, respectively for IL, RL and RU in Africa. Although rice yield gaps in Africa can be substantially reduced by introduction of integrated GAPs to farmers, there is large difference between model-based yield gaps and yield gain obtained by integrated GAPs. Further efforts are needed to identify factors causing this difference. We recommend a research and development focus on rainfed lowland rice systems, which have the largest model-based yield gaps by partially converting them to irrigated systems, and on improving nutrient use efficiencies and closing nutrient cycles.

Yield and Resource Utilization Efficiency Gap in Early Maturing Japonica Rice Cultivars under Different Management Strategies—A Different Location Investigation

High input costs and poor management options have resulted in a large rice yield gap. Thus, there is a need to reduce production costs and improve resource-use efficiency by using new cultivation techniques at different locations. The objective of this study was to determine yield and utilization efficiency gaps in early maturing japonica rice under four treatments; no nitrogen application (N0), local farmer practice (FP), high-yield, high-efficiency practice (HYP), and super-high-yield practice (SHY). The average yields under N0, FP, HYP, and SHY were 5012, 7356, 8448, and 9629 kg ha−1, respectively. Differences among treatments were as: N0 to FP (gap 1); FP to HYP (gap 2); and HYP to SHY (gap 3). Yield gaps 1, 2, and 3 were 2337, 1092, and 1181 kg ha−1, respectively. Yield gap was positively associated with panicles per square meter. Yield under HYP and SHY was 14.8% and 30.9% higher than that under FP, respectively. This increase in yield was mainly associated with a higher number of panicles. For resources, gaps 1, 2, and 3 were as follows: water-use efficiency, 0.1706, 0.1513, and 0.1089 kg m−3; radiation-use efficiency, 0.3285%, 0.1780%, and 0.0941%; and heat-use efficiency, 1.8685, 1.0339, and 0.8798 kg °C−1 d−1 ha−1, respectively. The yield was positively correlated with water, radiation, and heat-use efficiencies. The differences in yield and resource-use efficiency were significant between sites. A reduction in yield and efficiency gaps can ensure sufficient panicle per square meter, stabilize grain number per panicle, and increase harvest index and biomass. Overall, HYP is a promising option to increase the yield of early maturing japonica rice yield in cold regions.