Exponential relationship between N2O emission and fertilizer nitrogen input and mechanisms for improving fertilizer nitrogen efficiency under intensive plastic-shed vegetable production in China: A systematic analysis

SummaryExperiments on winter wheat were made from 1980 to 1982 to test fungicide and aphicide sprays in factorial combination with four amounts of nitrogen fertilizer, applied in either one or two dressings in spring. The wheat was grown on three farms with contrasting calcareous clay soils from three soil series; each year it followed a 2-year break on one farm, a cereal rotation on the second and continuous wheat on the third. Soils were sampled to a depth of 0·9 m at seedling emergence in autumn, and again in February and April, to determine the NO3-N and NH4-N in each 0·3 m horizon. Crops were sampled for growth analysis at monthly intervals from March onwards and analysed for nitrogen content. Measurements of stem sap NO3-N concentration were also made at 2-weekly intervals from February or March to late June.Measurements of soil mineral N were used to calculate the fertilizer nitrogen dressings used in the experiments. The concentration of NO3-N in the stem sap was related to NO3-N in soil; concentiations remained high until most of the soil NO3-N had been removed by the crop. The time at which stem sap NO3-N concentration declined therefore acted as an index of soil N supply, and the data showed that fertilizer-N was needed when the NO3-N concentration fell below a 200 μg/ml threshold. Yields benefited from N applied in February or March only when stem sap NO3-N concentration fell below the threshold at this time.Apparent fertilizer nitrogen efficiency exceeded 70 % where yields were very large, but ranged between 53 and 64% where yields were smaller because either soil physical problems or disease restraints were present.A severe attack by take-all (Gaeumannomyces cerealis) caused premature senescence at one centre in 1980; this apparently prevented previously assimilated nitrogen from moving into the grain.

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Comparison of fertilizer nitrogen efficiency among field crops

Soil Science & Plant Nutrition ◽

10.1080/00380768.1984.10434683 ◽

1984 ◽

Vol 30 (2) ◽

pp. 199-208 ◽

Cited By ~ 8

Author(s):

Akira Tanaka ◽

Junichi Yamaguchi ◽

Shu Miura ◽

Hiroyuki Tamaru

Keyword(s):

Nitrogen Efficiency ◽

Fertilizer Nitrogen ◽

Field Crops

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Nitrogen balance studies in rice using 15N-labelled urea and urea supergranules

The Journal of Agricultural Science ◽

10.1017/s0021859600084707 ◽

1989 ◽

Vol 113 (1) ◽

pp. 119-121 ◽

Cited By ~ 7

Author(s):

S. K. Mohanty ◽

S. P. Chakravorti ◽

A. Bhadrachalam

Keyword(s):

Nitrogen Balance ◽

Rice Field ◽

Nitrogen Efficiency ◽

Seasonal Effects ◽

Split Application ◽

Deep Placement ◽

Fertilizer Nitrogen ◽

Urea Supergranules ◽

The Poor ◽

Different Types

Recovery of applied nitrogen by the rice crop is invariably low, often 30–50% (Prasad & De Datta 1979). The poor recovery has been attributed to different types of losses occurring in the rice field. Recovery improved with split application, delayed application or deep placement (Pillai & Vamadevan 1978; Craswell & Vlek 1979), indicating that the management factor plays an important role in increasing fertilizer nitrogen efficiency. To investigate such factors, and seasonal effects, field experimentswere carried out using 15N-labelled urea (PU) and urea supergranules (USG). The recovery of fertilizer 15N by the plant and retention in the soil were studied in both dry and wet seasons.

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VEGETABLE GROWING INDUSTRY IN THE FOOD PROCESSING SYSTEM THE MARKET: FEATTURES, TRENDS, AND PROSPECTS

Intellect XXІ ◽

10.32782/2415-8801/2021-3.10 ◽

2021 ◽

Author(s):

Viktoriia Rud

Keyword(s):

Food Security ◽

Processing System ◽

Rate Of Change ◽

Practical Significance ◽

General Strategy ◽

Vegetable Production ◽

Systematic Analysis ◽

The World ◽

The Future ◽

Food Market

The analysis of the current state of vegetable production in Ukraine is chosen for the purpose, the main problems of its development in modern conditions are established; The role of vegetable growing in the food market system has been studied and the directions of stabilization and increase of efficiency of functioning of the vegetable subcomplex have been determined. The methodological basis of the study were scientific papers on the formation and functioning of the vegetable market. The following methods were used: dialectical, abstract-logical, systematic analysis (theoretical generalizations and formation of conclusions); mathematical and statistical, the method of expert assessments (when establishing a rating assessment of the level of yield of vegetables). Results: The article analyzes the indicators of production, sown areas and yield levels of major crops for the period 2000-2019 in Ukraine, Europe and the world, outlines the general strategy of the vegetable industry, identifies the features of the vegetable and food subcomplex in system of the national food market. Aspects of formation of food security of Ukraine on the basis of an estimation of levels of production and consumption, volumes of export and import are considered. The level of food security of the country in 2015 and 2019 was determined by calculating the indicator of economic affordability of products and indicators of adequacy of consumption of different groups of products in Ukraine in 2019. The reasons for the unsatisfactory condition of the vegetable and food subcomplex are analyzed, the general strategy and priority directions of development of vegetable and melon growing and processing industry for the period up to 2025 are stated, the volumes of vegetable and melon production for the future are determined. The scientific novelty is to establish trends in the development of the vegetable industry for the 20-year period (2000-2019) in Ukraine, CIS countries, regions of the world and compare the rate of change of these indicators for this period. The practical significance of the publication is to identify the main problems of development of the vegetable industry in the food market and to identify ways to solve problems in the future.

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