scholarly journals Long-term use of potassium fertilizer for vegetable crops in the upcountry intermediate zone

1997 ◽  
Vol 25 (1) ◽  
pp. 59
Author(s):  
J.D.H. Wijewardena ◽  
S.L. Amarasiri
Keyword(s):  
Intermediate Zone ◽  
Vegetable Crops ◽  
Potassium Fertilizer

Functional differentiation of nitrate-reducing isolates regulated by long-term fertilization in a rice paddy soil

2020 ◽  
pp. 1-9
Author(s):  
Xing Chen ◽  
Yi Liu ◽  
Chunmei Liu ◽  
Wenzhao Zhang ◽  
Hongling Qin ◽  
...  
Keyword(s):  
Growth Medium ◽  
Normal Growth ◽  
Rice Paddy ◽  
Functional Differentiation ◽  
Fertilizer Treatment ◽  
Potassium Fertilizer ◽  
Nutritional Conditions ◽  
Nitrate Reducers ◽  
Nitrite Production

Fertilization can cause obvious shifts in nitrate-reducing community composition in agricultural ecosystems; however, little is known about the behaviors and functional characters of isolated nitrate reducers adapted to a specific environment. In this study, 849 nitrate-reducing bacteria were isolated from various fertilization treatments in a long-term paddy field experiment; the isolates were further characterized in functions with both culture-dependent and independent methodologies. The results showed that CK (no fertilizer) treatment had four genera with even relative abundance, whereas the other three treatments had their own predominant genera with Chromobacterium in nitrogen (N) fertilizer, Serratia in NPK (nitrogen, phosphorus, and potassium fertilizer) and Enterobacter in NPKC treatment (NPK plus rice straw). The isolates of Serratia and Enterobacter grew faster and produced significantly more nitrites than those of Chromobacterium and Burkholderia in the normal growth medium, suggesting that the dominant isolates from nutrient-rich environment, such as NPK and NPKC treatments, are better adapted to high nutritional conditions. On the contrary, the strains of Chromobacterium and Burkholderia possessed stronger nitrite production ability in comparison with the isolates of Serratia and Enterobacter in the diluted growth medium, indicating that the selected isolates from CK and N treatments have the capability to develop under nutrient-limiting conditions. Our results indicated that the behaviors and functions of nitrate reducers appears to be important in adapting to their dwelling habitats.

scholarly journals Effects of Vegetable Fields on the Spatial Distribution Patterns of Metal(loid)s in Soils Based on GIS and Moran’s I

2019 ◽  
Vol 16 (21) ◽  
pp. 4095
Author(s):  
Qiang Wang ◽  
Shanlian Yang ◽  
Menglei Zheng ◽  
Fengxiang Han ◽  
Youhua Ma
Keyword(s):  
Spatial Distribution ◽  
Organic Fertilizer ◽  
Distribution Patterns ◽  
Moran’S I ◽  
Vegetable Production ◽  
Vegetable Crops ◽  
Moran's I ◽  
Spatial Distribution Patterns ◽  
Ph Decrease

Metal(loid) pollution in vegetable field soils has become increasingly severe and affects the safety of vegetable crops. Research in China has mainly focused on greenhouse vegetables (GV), while open field vegetables (OV) and the spatial distribution patterns of metal(loid)s in the surrounding soils have rarely been assessed. In the present study, spatial analysis methods combining Geographic Information Systems (GIS) and Moran’s I were applied to analyze the effects of vegetable fields on metal(loid) accumulation in soils. Overall, vegetable fields affected the spatial distribution of metal(loid)s in soils. In long-term vegetable production, the use of large amounts of organic fertilizer led to the bioconcentration of cadmium (Cd) and mercury (Hg), and long-term fertilization resulted in a significant pH decrease and consequent transformation and migration of chromium (Cr), lead (Pb), and arsenic (As). Thus, OV fields with a long history of planting had lower average pH and Cd, and higher average As, Cr, Hg, and Pb than GV fields, reached 0.93%, 10.1%, 5.8%, 3.0%, 80.8%, and 0.43% respectively. Due to the migration and transformation of metal(loid)s in OV soils, these should be further investigated regarding their abilities to reduce the accumulation of metal(loid)s in soils and protect the quality of the cultivated land.

Measuring Light Interception and the Efficiency of Light Utilization by the Coconut Palm (Cocos nucifera)

1992 ◽  
Vol 28 (3) ◽  
pp. 273-285 ◽  
Author(s):  
J. R. J. Moss
Keyword(s):  
Cocos Nucifera ◽  
Genetic Selection ◽  
Efficiency Index ◽  
Field Trials ◽  
Light Interception ◽  
Dry Season ◽  
Potassium Fertilizer ◽  
Sole Cropping ◽  
One Year

SummaryA mobile sampling method was used to measure the amount of photosynthetically active radiation (PAR) transmitted through the canopies of coconut palms in two long term field trials. PAR transmissions were measured at approximately monthly intervals for one year. Fractional interception of light was found to vary considerably between months, and to be associated with frond shedding caused by dry season water stress. Palms receiving potassium fertilizer intercepted more light and replaced leaf area lost during the dry season more rapidly than those receiving no potassium. Palms planted at a higher density intercepted more light and carried more fronds per palm, but intercepted less light per frond than those planted at a lower density. The ratio of moles of carbohydrate yield to moles of intercepted PAR quanta was calculated for six plots of hybrid palms, giving a dimensionless light efficiency index (LEI) comparable to harvest index. Mean LEI for all plots was 1.275 × 10−4 and was found to increase with increased light interception, results suggesting that there is a basal level of light interception below which no yield is produced. The potential for using LEI in agronomic experimentation on sole cropping and multicropping and as a criterion for genetic selection of coconut palms is discussed.

scholarly journals Management of the water regime of soil to increase the vegetable crops yield with different irrigation methods in the south of Russia

2021 ◽  
Vol 282 ◽  
pp. 05001
Author(s):  
Evgeny Khodiakov ◽  
Askar Akhmedov ◽  
Evgeny Borovoy ◽  
Sergey Milovanov ◽  
Kirill Bondarenko
Keyword(s):  
Drip Irrigation ◽  
Water Regime ◽  
Mineral Fertilizers ◽  
Vegetable Crops ◽  
Irrigation Regime ◽  
Moisture Capacity ◽  
Irrigation Network ◽  
Volgograd Region ◽  
Crops Yield

Long-term researches on the cultivation of vegetable crops with different methods of irrigation in the Volgograd region have shown that their yield was primarily closely related to the improvement of the water regime of the soil. Its efficiency using drip irrigation increased with the introduction of mineral fertilizers, and using subsurface irrigation - with an improvement of the location of the irrigation network. The highest yield of beet with drip irrigation (82.4 t / ha) was obtained with an increase of the Soil Pre-Irrigation Moisture (SPIM) to 85% of Full Moisture Capacity (FMC) and fertilization doses - to N235P140K130 kg/ha. The highest yield of courgettes with drip irrigation of 83.7 t / ha was obtained while maintaining the similar irrigation regime and the quantity of fertilizers N240P99K110 kg/ha.The maximum cabbage yield in our experience with drip irrigation of 83.1 t / ha was achieved using the option that combines the maintenance of the irrigation regime 80-90-80 %FMC with the application of fertilizers at doses of N110P50K140 kg / ha. The highest yield of radish with subsurface irrigation of 79.8 t / ha was obtained while maintaining SPIM 85 % FMC in the field with the location of subsurface humidifiers at a distance of 1.2 m from each other.

scholarly journals Impact of long term organic sources on physical properties and yield of vegetable crops in Nagpur district

2020 ◽  
Vol 8 (2) ◽  
pp. 2723-2727
Author(s):  
Babita Patel ◽  
RM Ghodpage ◽  
J Patel ◽  
SG Karwade ◽  
AA Ekka
Keyword(s):  
Physical Properties ◽  
Vegetable Crops ◽  
Nagpur District

Monitoring the Resistance of the Beet Armyworm (Lepidoptera: Noctuidae) to Four Insecticides in Southern China from 2014 to 2018

2021 ◽  
Author(s):  
Pan Wang ◽  
Fan Yang ◽  
Yong Wang ◽  
Li-Lin Zhou ◽  
Hai-Bo Luo ◽  
...  
Keyword(s):  
High Resistance ◽  
Southern China ◽  
Rapid Development ◽  
Beet Armyworm ◽  
Vegetable Crops ◽  
Resistance Patterns ◽  
Low Levels ◽  
Moderate Resistance ◽  
Lepidoptera Noctuidae

Abstract The beet armyworm Spodoptera exigua (Hübner) is a serious polyphagous pest that infests vegetable crops worldwide and has rapidly developed resistance due to its long-term exposure to insecticides. The current resistance statuses to four insecticides exhibited by three field populations of beet armyworms collected in southern China from 2014 to 2018 were investigated. Monitoring data from five consecutive years demonstrated that all three tested S. exigua populations developed extremely high resistance to chlorantraniliprole in 2018 (220.58- to 2,597.39-fold). Two populations (Baiyun and Fengxian) developed low to moderate resistance to spinosad, whereas the Huangpi population remained susceptible (except in 2014, with RR of 6.11-fold). The RR of the Fengxian and Baiyun populations to indoxacarb steadily increased over the years, whereas that of the Huangpi population increased relatively slowly. The Baiyun and Fengxian populations developed moderate to high resistance to indoxacarb and methoxyfenozide, whereas the Huangpi population exhibited susceptibility to low resistance (1.06- to 6.45-fold) to indoxacarb and susceptibility to moderate resistance (1.53- to 14.22-fold) to methoxyfenozide. These results suggest that chlorantraniliprole should not be employed to control this pest in southern China. Reduced use of indoxacarb and methoxyfenozide or the use of alternating insecticides with low levels of resistance is recommended. Spinosad remains an effective insecticide for the management of S. exigua. To avoid the rapid development of insecticide resistance, rotations of insecticides with low levels of resistance and different modes of action based on the resistance patterns of S. exigua should be performed in southern China.

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