Potato Yield Gaps in North Korea and Strategies to Close the Gaps

Potato has become one of the staple crops to improve food security in North Korea since the late 1990s. However, the potato yield has been stagnated around 11–12 t ha−1 for several decades, and a food shortage is still a primary issue in North Korea. Yield gap analyses were carried out using the SUBSTOR-potato model to quantify the potato yield gaps and explore the potential ways to close the yield gaps in two different cropping seasons in North Korea (early- and main-season potatoes). Yield gaps were estimated to be around 80% for both early- and main-season potatoes. Early-season potato yield was substantially determined by water or nitrogen supplies, depending on the year’s weather condition (i.e., with or without spring drought). Irrigation during the vegetative stage could effectively reduce the year-to-year variation in yield as well as the yield gap (+7.0 t ha−1, +66.1%). Meanwhile, additional nitrogen fertilizer in the early-season potatoes was less effective compared to that in the main-season potatoes. For the main-season potatoes, where precipitation was sufficient, the primary limiting factor of yield was nitrogen supply. Since heavy rainfall aggravated nitrogen leaching, additional nitrogen fertilizer is recommended as a top dressing rather than a basal dressing. Additional top dressing at 50 days after planting with the current amount of nitrogen fertilizer was expected to increase the main-season potato yield by 42.0 t ha−1 (+191.4%). This study highlights that the primary limiting factor of potato yield may differ between the cropping seasons. Therefore, our findings suggest that different agronomic strategies should be applied for different cropping seasons to improve potato production in North Korea, where agronomic resources are limited.

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Multi-scale assessment of winter wheat yield gaps with an integrated evaluation framework in the Huang-Huai-Hai farming region in China

The Journal of Agricultural Science ◽

10.1017/s0021859619000856 ◽

2019 ◽

Vol 157 (6) ◽

pp. 523-536

Author(s):

S. Li ◽

J. Liu ◽

M. Shang ◽

H. Jia ◽

Y. Feng ◽

...

Keyword(s):

Winter Wheat ◽

Wheat Yield ◽

Evaluation Framework ◽

High Yield ◽

Limiting Factor ◽

Yield Gap ◽

Multi Scale ◽

Winter Wheat Yield ◽

Yield Gaps ◽

Attainable Yield

AbstractQuantifying reasonable crop yield gaps and determining potential regions for yield improvement can facilitate regional plant structure adjustment and promote crop production. The current study attempted to evaluate the yield gap in a region at multi-scales through model simulation and farmer investigation. Taking the winter wheat yield gap in the Huang-Huai-Hai farming region (HFR) for the case study, 241 farmers’ fields in four typical high-yield demonstration areas were surveyed to determine the yield limitation index and attainable yield. In addition, the theoretical and realizable yield gap of winter wheat in 386 counties of the HFR was assessed. Results showed that the average field yield of the demonstration plots was 8282 kg/ha, accounting for 0.72 of the potential yield, which represented the highest production in the region. The HFR consists of seven sub-regions designated 2.1–2.7: the largest attainable yield gap existed in the 2.6 sub-region, in the southwest of the HFR, while the smallest was in the 2.2 sub-region, in the northwest of the HFR. With a high irrigated area rate, the yield gap in the 2.2 sub-region could hardly be reduced by increasing irrigation, while a lack of irrigation remained an important limiting factor for narrowing the yield gap in 2.3 sub-region, in the middle of the HFR. Therefore, a multi-scale yield gap evaluation framework integrated with typical field survey and crop model analysis could provide valuable information for narrowing the yield gap.

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Control of flowering in two commercial sugar-cane varieties

The Journal of Agricultural Science ◽

10.1017/s0021859600047286 ◽

1984 ◽

Vol 103 (2) ◽

pp. 333-338 ◽

Cited By ~ 1

Author(s):

M. A. El Manhaly ◽

O. Fadayomi ◽

Y. A. Abayomi ◽

M. O. Olofinboba

Keyword(s):

Nitrogen Fertilizer ◽

Sugar Cane ◽

Initiation Time ◽

Nitrogen Application ◽

Commercial Sugar ◽

Cropping Seasons ◽

Additional Nitrogen

SUMMARYExperiments were conducted over two cropping seasons at the Sugar Cane Estate of the Nigerian Sugar Company, Bacita, Nigeria to determine the effectiveness of additional nitrogen fertilizer, chemical sprays and delayed planting in controlling flowering in two commercial sugar-cane varieties (Co. 1001 andCp. 29/116). Application of 150 and 250 kg N/ha, 8 weeks before initiation, reduced flowering in Co. 1001 by up to 13·5 and 11 % respectively. Flowering was as low as 2% in some of the above treatments while the average flowering in plots with no additional nitrogen application was more than 80%. imilarly, application of diuron (4·0 kg/ha) and paraquat (0'5 kg/ha) to the top leaves (3 weeks before initiation) of Co. 1001 reduced flowering in this variety up to 45 and 35% respectively. Neither the application of diuron and paraquat nor additional nitrogen fertilizer sufficiently reduced flowering in Cp. 29/116. The time of planting affected flowering. Over 85% flowering was observed in November 1982 from Co. 1001 fields planted in January 1982 (10 months before initiation time). However, fields of the same variety planted in June 1982 (4 months before initiation time) did not show any initiation until harvest in May 1983. The implications of the above results are discussed.

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Wheat yield gaps across smallholder farming systems in Ethiopia

Agronomy for Sustainable Development ◽

10.1007/s13593-020-00654-z ◽

2021 ◽

Vol 41 (1) ◽

Author(s):

João Vasco Silva ◽

Pytrik Reidsma ◽

Frédéric Baudron ◽

Moti Jaleta ◽

Kindie Tesfaye ◽

...

Keyword(s):

Stochastic Frontier Analysis ◽

Stochastic Frontier ◽

Wheat Yield ◽

Farming Systems ◽

Smallholder Farming ◽

Yield Gap ◽

Frontier Analysis ◽

Ecological Zones ◽

Relative Contribution ◽

Yield Gaps

AbstractWheat yields in Ethiopia need to increase considerably to reduce import dependency and keep up with the expected increase in population and dietary changes. Despite the yield progress observed in recent years, wheat yield gaps remain large. Here, we decompose wheat yield gaps in Ethiopia into efficiency, resource, and technology yield gaps and relate those yield gaps to broader farm(ing) systems aspects. To do so, stochastic frontier analysis was applied to a nationally representative panel dataset covering the Meher seasons of 2009 and 2013 and crop modelling was used to simulate the water-limited yield (Yw) in the same years. Farming systems analysis was conducted to describe crop area shares and the availability of land, labour, and capital in contrasting administrative zones. Wheat yield in farmers’ fields averaged 1.9 t ha− 1 corresponding to ca. 20% of Yw. Most of the yield gap was attributed to the technology yield gap (> 50% of Yw) but narrowing efficiency (ca. 10% of Yw) and resource yield gaps (ca. 15% of Yw) with current technologies can nearly double actual yields and contribute to achieve wheat self-sufficiency in Ethiopia. There were small differences in the relative contribution of the intermediate yield gaps to the overall yield gap across agro-ecological zones, administrative zones, and farming systems. At farm level, oxen ownership was positively associated with the wheat cultivated area in zones with relatively large cultivated areas per household (West Arsi and North Showa) while no relationship was found between oxen ownership and the amount of inputs used per hectare of wheat in the zones studied. This is the first thorough yield gap decomposition for wheat in Ethiopia and our results suggest government policies aiming to increase wheat production should prioritise accessibility and affordability of inputs and dissemination of technologies that allow for precise use of these inputs.

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Methodology of Analyzing Maize Density Loss in Smallholder’s Fields and Potential Optimize Approach

Agriculture ◽

10.3390/agriculture11060480 ◽

2021 ◽

Vol 11 (6) ◽

pp. 480

Author(s):

Zhichao An ◽

Chong Wang ◽

Xiaoqiang Jiao ◽

Zhongliang Kong ◽

Wei Jiang ◽

...

Keyword(s):

Decision Making ◽

Food Security ◽

Zea Mays L ◽

Plant Density ◽

Density Difference ◽

Yield Gap ◽

Farmer Decision Making ◽

Yield Gaps ◽

Farmer Survey ◽

Experimental Plots

Increasing plant density is a key measure to close the maize (Zea mays L.) yield gap and ensure food security. However, there is a large plant density difference in the fields sown by agronomists and smallholders. The primary cause of this phenomenon is the lack of an effective methodology to systematically analyze the density loss. To identify the plant density loss processes from experimental plots to smallholder fields, a research methodology was developed in this study involving a farmer survey and measurements in a smallholder field. The results showed that the sowing density difference caused by farmer decision-making and plant density losses caused by mechanical and agronomic factors explained 15.5%, 5.5% and 6.8% of the plant density difference, respectively. Changing smallholder attitudes toward the value of increasing the plant density could help reduce this density loss and increase farm yields by 12.3%. Therefore, this methodology was effective for analyzing the plant density loss, and to clarify the primary causes of sowing density differences and plant density loss. Additionally, it was beneficial to identify the priorities and stakeholders who share responsibility for reducing the density loss. The methodology has wide applicability to address the sowing density differences and plant density loss in other areas to narrow crop yield gaps and ensure food security.

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The soybean yield gap in Brazil – magnitude, causes and possible solutions for sustainable production

The Journal of Agricultural Science ◽

10.1017/s0021859615000313 ◽

2015 ◽

Vol 153 (8) ◽

pp. 1394-1411 ◽

Cited By ~ 61

Author(s):

P. C. SENTELHAS ◽

R. BATTISTI ◽

G. M. S. CÂMARA ◽

J. R. B. FARIAS ◽

A. C. HAMPF ◽

...

Keyword(s):

Water Deficit ◽

Precision Agriculture ◽

Crop Management ◽

Sustainable Production ◽

Biodiesel Production ◽

Yield Gap ◽

Soybean Yield ◽

South Central ◽

Crop Simulation ◽

Yield Gaps

SUMMARYBrazil is one of the most important soybean producers in the world. Soybean is a very important crop for the country as it is used for several purposes, from food to biodiesel production. The levels of soybean yield in the different growing regions of the country vary substantially, which results in yield gaps of considerable magnitude. The present study aimed to investigate the soybean yield gaps in Brazil, their magnitude and causes, as well as possible solutions for a more sustainable production. The concepts of yield gaps were reviewed and their values for the soybean crop determined in 15 locations across Brazil. Yield gaps were determined using potential and attainable yields, estimated by a crop simulation model for the main maturity groups of each region, as well as the average actual famers’ yield, obtained from national surveys provided by the Brazilian Government for a period of 32 years (1980–2011). The results showed that the main part of the yield gap was caused by water deficit, followed by sub-optimal crop management. The highest yield gaps caused by water deficit were observed mainly in the south of Brazil, with gaps higher than 1600 kg/ha, whereas the lowest were observed in Tapurah, Jataí, Santana do Araguaia and Uberaba, between 500 and 1050 kg/ha. The yield gaps caused by crop management were mainly concentrated in South-central Brazil. In the soybean locations in the mid-west, north and north-east regions, the yield gap caused by crop management was <500 kg/ha. When evaluating the integrated effects of water deficit and crop management on soybean yield gaps, special attention should be given to Southern Brazil, which has total yield gaps >2000 kg/ha. For reducing the present soybean yield gaps observed in Brazil, several solutions should be adopted by growers, which can be summarized as irrigation, crop rotation and precision agriculture. Improved dissemination of agricultural knowledge and the use of crop simulation models as a tool for improving crop management could further contribute to reduce the Brazilian soybean yield gap.

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Early Season Nitrogen Fertilizer Recovery by Corn within a Furrow-Irrigated Production System

Soil Science Society of America Journal ◽

10.2136/sssaj2016.08.0245 ◽

2017 ◽

Vol 81 (4) ◽

pp. 806-813 ◽

Cited By ~ 1

Author(s):

Chester E. Greub ◽

Trenton L. Roberts ◽

Nathan A. Slaton ◽

Jason P. Kelley

Keyword(s):

Nitrogen Fertilizer ◽

Production System ◽

Early Season ◽

Fertilizer Recovery

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Influence of fertilizers and of the autumn tillage method on potato yield and phytopathologiс characteristics of tubers

Agricultural science Euro-North-East ◽

10.30766/2072-9081.2021.22.3.393-400 ◽

2021 ◽

Vol 22 (3) ◽

pp. 393-400

Author(s):

V. I. Titova ◽

E. T. Akopdzhanyan

Keyword(s):

Field Experiment ◽

Ammonium Nitrate ◽

Nitrogen Fertilizer ◽

Growing Season ◽

Potato Yield ◽

Loamy Soil ◽

Pest Damage ◽

Tillage Method ◽

Nizhny Novgorod Region ◽

Production Conditions

The field experiment on identifying differences in the effect of the herbicide and foliar feeding of plants with liquid nitrogen fertilizer (UAN-32) against the background of autumn tillage with a cultivator or plow on potato yield and phytopathologic characteristics of tubers during storage was carried out in 2019-2020 in the Nizhny Novgorod region. The experiment was laid on sod-podzolic sandy loamy soil in production conditions on two varieties of potato ‒ the super-early Сolomba variety and the medium-early Innovator variety grown for seeds. The variants under study were surface application of the soil herbicide Gezagard in a tank mixture with UAN-32 and foliar feeding of plants with UAN-32 (N42) during the growing season against the background of N42P42K169 (calcium chloride in autumn + ammonium nitrate phosphate in spring). The results indicate that the background fertilization provides the yield of Colombа variety potato of 20.7-29.0 t/ha, the Innovator variety – 17.4-23.1 t/ha. The use of the herbicide is more effective during autumn tillage with a cultivator, providing an increase in yield of 28-37 % on both potato varieties, feeding of plants with UAN-32 contributes to an increase in yield (8-10 %) only on the Сolomba variety. Plowing the soil for potatoes helps to avoid the pest damage of tubers and to reduce their susceptibility to rhizoctonia by 6-27 %, to wet rot ‒ up to 55 %. In general, it has been established that due to autumn plowing with fertilization at a dose of N42P42K169, it is possible to obtain an increase in potato yield exceeding the increase provided both by herbicides and the use of foliar feeding of potatoes.

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Diagnosing the Climatic and Agronomic Dimensions of Rain-Fed Oat Yield Gaps and Their Restrictions in North and Northeast China

Sustainability ◽

10.3390/su11072104 ◽

2019 ◽

Vol 11 (7) ◽

pp. 2104 ◽

Cited By ~ 1

Author(s):

Chong Wang ◽

Jiangang Liu ◽

Shuo Li ◽

Ting Zhang ◽

Xiaoyu Shi ◽

...

Keyword(s):

Northeast China ◽

Crop Production ◽

Crop Yields ◽

Climatic Conditions ◽

Planting Density ◽

Limiting Factors ◽

High Yield ◽

Yield Gap ◽

Potential Yield ◽

Yield Gaps

Confronted with the great challenges of globally growing populations and food shortages, society must achieve future food security by increasing grain output and narrowing the gap between potential yields and farmers’ actual yields. This study attempts to diagnose the climatic and agronomic dimensions of oat yield gaps and further to explore their restrictions. A conceptual framework was put forward to analyze the different dimensions of yield gaps and their limiting factors. We quantified the potential yield (Yp), attainable yield (Yt), experimental yield (Ye), and farmers’ actual yield (Ya) of oat, and evaluated three levels of yield gaps in a rain-fed cropping system in North and Northeast China (NC and NEC, respectively). The results showed that there were great differences in the spatial distributions of the four kinds of yields and three yield gaps. The average yield gap between Yt and Ye (YG-II) was greater than the yield gap between Yp and Yt (YG-I). The yield gap between Ye and Ya (YG-III) was the largest among the three yield gaps at most sites, which indicated that farmers have great potential to increase their crop yields. Due to non-controllable climatic conditions (e.g., light and temperature) for obtaining Yp, reducing YG-I is extremely difficult. Although YG-II could be narrowed through enriching soil nutrients, it is not easy to improve soil quality in the short term. In contrast, narrowing YG-III is the most feasible for farmers by means of introducing high-yield crop varieties and optimizing agronomic managements (e.g., properly adjusting sowing dates and planting density). This study figured out various dimensions of yield gaps and investigated their limiting factors, which should be helpful to increase farmers’ yields and regional crop production, as long as these restrictions are well addressed.

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Causes Of Yield Gaps And Strategies For Minimizing The Gaps In Different Crops Of Bangladesh

Bangladesh Journal of Agricultural Research ◽

10.3329/bjar.v36i3.9274 ◽

1970 ◽

Vol 36 (3) ◽

pp. 469-476 ◽

Cited By ~ 12

Author(s):

Mohammad H Mondal

Keyword(s):

New Technologies ◽

High Yield ◽

Credit System ◽

Yield Gap ◽

Related Factors ◽

Integrated Crop Management ◽

Yield Gaps ◽

The Difference ◽

The Government ◽

Extension Agencies

The concept of yield gaps originated from the studies conducted by IRRI in the seventies. The yield gap discussed in this paper is the difference between the potential farm yield and the actual average farm yield. In Bangladesh, yield gaps exist in different crops ranging up to 60%. According to the recent study conducted by BRRI, the yield gap in rice was estimated at 1.74 t/ha. The existence of yield gaps was as well observed in rice, mustard, wheat and cotton in India. In India, yield gap varied from 15.5 to 60% with the national average gap of 52.3% in irrigated ecosystem. The yield gaps are mainly caused by biological, socio-economic, climate and institutional/policy related factors. Different strategies, such as integrated crop management (1CM) practices, timely supply of inputs including credit to farmers, research and extension collaboration to transfer the new technologies have been discussed as strategies to minimize yield gaps. Suggestions have been made to make credit available to resource-poor small farmers to buy necessary inputs. Reducing transaction cost, simplifying lending procedures and strengthening monitoring mechanism of the current credit system are, however, essential to enable the farmers to avail the credit facility. Efforts should be made to update farmers’ knowledge on the causes of yield gaps in crops and measures to narrow the gaps through training, demonstrations, field visits and monitoring by extension agencies to achieve high yield. The government should realize that yield gaps exist in different crops of Bangladesh and therefore, explore the scope to increase production as well as productivity of crops by narrowing the yield gap and thereby ensure food security. Keywords: Yield gaps; strategies; crops of Bangladesh. DOI: http://dx.doi.org/10.3329/bjar.v36i3.9274 BJAR 2011; 36(3): 469-476

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