scholarly journals Duncan Joseph Greenwood. 16 October 1932 — 13 February 2010

Author(s):  
Ian G. Burns

During his 55-year career as a highly distinguished scientist, Duncan Greenwood made a major contribution to the field of soil science and plant nutrition. His early studies on soil aeration revolutionized thinking on the mechanisms by which oxygen influences the activity of microorganisms and their metabolism of organic substances in structured soil. His ideas resulted in the ‘micro-site concept of soil aeration’, which is still widely accepted today. Later he turned his attention to the nutritional requirements of vegetable crops at a time when the horticultural industry was starting to introduce inorganic fertilizers. He developed a novel static model of N, P and K response, which he used to produce the first scientifically based inorganic fertilizer recommendations for 23 different vegetable crops. Not satisfied with this major development, Duncan started to create more sophisticated dynamic models using novel widely applicable relationships that took more account of the effects of weather on nutrient behaviour in the soil and plant. He not only used these to provide important insights into many of the complex interacting processes involved, but also incorporated them into some of the first computer-based decision support systems for practical site-specific fertilizer advice for the vegetable growing industry. The application of these advances had an important effect on the efficiency of crop production and the reduction of associated environmental impacts. Duncan continued to devise new models for nutrient and water use throughout the rest of his career and to explore ways of applying them in different areas of soil and crop science.

EDIS ◽  
2019 ◽  
Vol 2019 (6) ◽  
pp. 5
Author(s):  
Hai Liu ◽  
Guodong Liu

Asian vegetable crops are rapidly expanding in Florida in the last decade due to their health benefits combined with their high profitability. These crops can help increase vegetable growers’ income and diversify Florida’s crop production, and they are new to most Floridians. This new 5-page article provides a general overview of bok choy for vegetable growers, crop consultants, certified crop advisors, Extension agents, and graduate students. Written by Hai Liu and Guodong Liu and published by the UF/IFAS Horticultural Sciences Department.https://edis.ifas.ufl.edu/hs1337


2021 ◽  
Vol 22 (22) ◽  
pp. 12245
Author(s):  
Manoj Kumar ◽  
Ved Prakash Giri ◽  
Shipra Pandey ◽  
Anmol Gupta ◽  
Manish Kumar Patel ◽  
...  

Vegetable cultivation is a promising economic activity, and vegetable consumption is important for human health due to the high nutritional content of vegetables. Vegetables are rich in vitamins, minerals, dietary fiber, and several phytochemical compounds. However, the production of vegetables is insufficient to meet the demand of the ever-increasing population. Plant-growth-promoting rhizobacteria (PGPR) facilitate the growth and production of vegetable crops by acquiring nutrients, producing phytohormones, and protecting them from various detrimental effects. In this review, we highlight well-developed and cutting-edge findings focusing on the role of a PGPR-based bioinoculant formulation in enhancing vegetable crop production. We also discuss the role of PGPR in promoting vegetable crop growth and resisting the adverse effects arising from various abiotic (drought, salinity, heat, heavy metals) and biotic (fungi, bacteria, nematodes, and insect pests) stresses.


2014 ◽  
Vol 1 (2) ◽  
pp. 81
Author(s):  
Lutfi Izhar ◽  
Anas D. Susila

<p>ABSTRACT</p><p><br />Vegetables are important agricultural commodities. Productivity of vegetables in Indonesia is still low. One effort that can be done is an application of specific fertilizer recommendations. Fertilizer recommendation based on soil analysis is still rarely for vegetable crops and need further development. The purpose of this paper is to describe some fertilizer recommendations based on soil analysis for vegetable crops. Three stages to consider in the assessment of the research such as soil incubation, correlation test, calibration test and fertilizer <br />recommendation statue. Application all this stages of soil method recommendation in Indonesia is still not widely applied. Two researches which were completed until the entire stage has been done for yard long beans and <br />tomatoes. Recommendations for tomatoes on Inceptisols soil type with very low nutrient status of soil K was 180 kg K2O ha- 1, a low K soil nutrient status was 131.4 kg K2O ha-1, soil K nutrient status was 82.2 kg K 2O ha-1. Yard <br />long bean that planted on Ultisol soil type with low soil P nutrient status was recommended by an application of 185.8 kg P2O5 ha-1, medium soil P nutrient status was added 174.9 kg P2O5 ha-1. Development of fertilizer recommendation based on soil testing to support agricultural development in Indonesia still has some problems and need some strategies for further research, application and dissemination in the future.</p><p>Key words: vegetables, soil test, fertilizer recommendation</p>


2021 ◽  
Vol 12 ◽  
Author(s):  
Rongkui Han ◽  
Maria José Truco ◽  
Dean O. Lavelle ◽  
Richard W. Michelmore

Plants undergo profound physiological changes when transitioning from vegetative to reproductive growth. These changes affect crop production, as in the case of leafy vegetables. Lettuce is one of the most valuable leafy vegetable crops in the world. Past genetic studies have identified multiple quantitative trait loci (QTLs) that affect the timing of the floral transition in lettuce. Extensive functional molecular studies in the model organism Arabidopsis provide the opportunity to transfer knowledge to lettuce to explore the mechanisms through which genetic variations translate into changes in flowering time. In this review, we integrated results from past genetic and molecular studies for flowering time in lettuce with orthology and functional inference from Arabidopsis. This summarizes the basis for all known genetic variation underlying the phenotypic diversity of flowering time in lettuce and how the genetics of flowering time in lettuce projects onto the established pathways controlling flowering time in plants. This comprehensive overview reveals patterns across experiments as well as areas in need of further study. Our review also represents a resource for developing cultivars with delayed flowering time.


2020 ◽  
pp. 24-27
Author(s):  
Maryna POLENKOVA

The paper defines the structural distribution of sown area of crops. The dynamics of production of cereals and legumes, sugar beets, sunflowers, potatoes, vegetables, fruits and berries. The clustering of regions of Ukraine under similar conditions of development of the enterprises of the agricultural sector specializing in crop production is carried out. According to the results of the analysis, 3 clusters were identified, which gave rise to the possibility of forming (developing) joint effective organizational and economic mechanisms to enhance the development of crop enterprises, favorable for implementation within the cluster. In the course of this study, we focus on the development trends of enterprises specializing in crop products. The lion's share (54.7 %) of sown areas falls on cereals and legumes. Technical crops occupy, which is 32.6 %, and potatoes, vegetables and melons – 6.5 %. It is important to note the long-term positive dynamics of production of cereals and legumes and the growth of production can be traced to all categories of farms – in farms and households. The production of sunflower and vegetable crops was also marked by positive dynamics. The decrease was observed in the production of sugar beets, potatoes, fruit and berry crops. In the context of the study, it is important to identify similar conditions (environment, resources, etc.) for the development of agricultural enterprises between the regions of Ukraine. For this purpose, multifactor statistical analysis (cluster analysis) of key factors of their development was used on the basis of a matrix of 25 selected indicators of development of enterprises specializing in crop production in all regions (600 indicators). To enhance the objectivity of the results, the analysis was conducted in 2010, 2015 and 2019. According to the results of the analysis, taxonomic groups (clusters) were singled out, which made it possible to single out similar regional conditions within each group. Since 2010, there have been significant changes in the regional distribution of Ukraine's agricultural potential. However, during 2015–2019 there is a relative stability in terms of resource provision and use within specific clusters. According to the results of the analysis, three clusters are distinguished: I. Volyn, Zakarpattia, Ivano-Frankivsk, Lviv, Rivne, Chernivtsi, as well as Donetsk and Luhansk regions. II. Dnipropetrovsk, Zhytomyr, Zaporizhia, Kyiv, Mykolaiv, Odesa, Ternopil, Kharkiv, Kherson, Khmelnytsky regions. III. Vinnytsia, Kirovohrad, Poltava, Sumy, Cherkasy and Chernihiv regions.


Engineering ◽  
2011 ◽  
Vol 03 (07) ◽  
pp. 778-785 ◽  
Author(s):  
Eduardo Coselli Vasco de Toledo ◽  
Edvaldo Rodrigo Morais ◽  
Delba Nisi Cosme Melo ◽  
Adriano Pinto Mariano ◽  
João F. C. A. Meyer ◽  
...  

Author(s):  
Lana dos Santos ◽  
Marcos Arenales ◽  
Alysson Costa ◽  
Ricardo Santos

This chapter is concerned with a set of optimization problems associated to crop rotation scheduling in the context of vegetable crop production according to some ecological criteria: no crop of the same botanic family is planted in sequence, green manure and fallow periods must be present in any schedule. A core mathematical model called the crop rotation scheduling model is proposed to represent these ecological criteria together with specific technical constraints associated to the growing of vegetable crops. Three optimization problems based on crop rotation schedules are written in detail in this chapter. For each problem, the authors present a general modeling framework and a solution methodology based on a technique known as column generation, which iteratively builds crop rotation plans for a number of plots. Some extensions are also presented, with the aim of incorporating additional characteristics found in production field conditions. This chapter ends with a brief discussion on a set of computational experiments and some suggestions for future research.


Agriculture ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 47 ◽  
Author(s):  
Massimiliano Renna ◽  
Angelo Signore ◽  
Francesco Montesano ◽  
Maria Gonnella ◽  
Pietro Santamaria

Biodiversity is the natural heritage of the planet and is one of the key factors of sustainable development, due to its importance not only for the environmental aspects of sustainability but also for the social and economic ones. The purpose of this Special Issue is to publish high-quality research papers addressing recent progress and perspectives while focusing on different aspects related to the biodiversity of vegetable crops. Original, high-quality contributions that have not yet been published, or that are not currently under review by other journals, have been gathered. A broad range of aspects such as genetic, crop production, environments, customs and traditions were covered. All contributions are of significant relevance and could stimulate further research in this area.


2020 ◽  
Author(s):  
Tonu Tonutare ◽  
Gert Kaldmae ◽  
Tiina Köster ◽  
Kadri Krebstein ◽  
Ako Rodima

&lt;p&gt;Due to increase of fertilizers prices and tightening of environmental protection requirements the need for efficient use of fertilizers has increased. At moment over the word huge number of different methods for determination of soil plant available phosphorus (PAP) are in use. Due to unequal extraction ability of extractants have each method own specific gradation to evaluate the soil P class. Allmost all widely used PAP extraction methods are developed in last century, mostly more than fifty years ago and often there is not possible to found information how the P status classes and fertilizer recommendations are determined for each method is determined.&lt;/p&gt;&lt;p&gt;The content of PAP in soil is difficult to estimate because soil pH has a strong effect to soil&amp;#160; - solution chemistry. Therefore extracting&amp;#160; soils with higly buffered solutions as for example Mehlich 3 can give overestimated results. The acidic Mehlich&amp;#160; 3 extactant can solubilize relatively insoluble Ca- Fe- and Al phosphates. Also the AL (acetate-lactate) method uses the buffered extraction solution and may influence the amount of extracted PAP. The most realistic conditions for PAP extraction can give the extraction solution which mimic the soil environment that has actively growing roots.&amp;#160;&lt;/p&gt;&lt;p&gt;The aim of our research was to investigate the extraction of PAP with extragent similar by chemical composition to soil solution with root exudates proposed by Haney et al (2010).&amp;#160; The obtained results were compared with Mehlich 3 and AL methods results.&amp;#160; &amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;Ref.: Haney, R.L., Haney, E.B., Hossner, L.R., Arnold, J,G. 2010. Modification to the New Soil Extractant H3A-1: A Multinutrient Extractant. Communications in Soil Science and Plant Analysis, 41:1513-1523.&lt;/p&gt;


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