scholarly journals Reproductive and vegetative responses of different accessions of Microlaena stipoides (Labill.) R.Br. to nitrogen applications and supplementary irrigation in southern Australia

2005 ◽  
Vol 27 (2) ◽  
pp. 151 ◽  
Author(s):  
I. H. Chivers ◽  
D. E. Aldous
Keyword(s):  
Soil Moisture ◽  
Seed Production ◽  
Irrigation Management ◽  
Summer Rainfall ◽  
Seed Supply ◽  
Australian Climate ◽  
Supplementary Irrigation ◽  
Microlaena Stipoides ◽  
Vegetative Characters ◽  
Nitrogen Treatments

Native grasses such as Microlaena stipoides (Labill.) R.Br. have the potential to play an important role in pastures, revegetation and as turfgrasses, but their use to date has been limited by seed supply. The purpose of this study was to investigate, (i) the effect of nitrogen fertilisation on M. stipoides seed production, (ii) the effect of irrigation on seed production, and (iii) the variation among accessions in response to these 2 factors. Microlaena stipoides accessions responded to added nitrogen with an increase in shoot growth, total amount of dry matter produced per plant and in reproductive characters at the end of the harvest season. Higher yields were recorded for high (split) nitrogen treatments in comparison to nil (control) or low nitrogen treatments, with added nitrogen extending seed production. Higher soil moisture regimes produced significantly more reproductive culms, more spikelets per culm, and more seeds per plant when compared to low soil moisture treatments. The frequency of irrigation had more effect on seed yield than the amount of water applied. Microlaena stipoides appears to have a 2–step mechanism for regulating the yield of its summer inflorescences namely; the plant initially responds to a high frequency of rainfall or irrigation events by initiating culms. Numbers of culms and florets per culm that reach maturity are dependent on the volume of water applied. Such a mechanism would assist in the adaptation of this grass to a southern Australian climate, which often exhibits an erratic summer rainfall. While there were differences among the accessions for both reproductive and vegetative characters, they gave a uniform response to the different nitrogen treatments. The responses of 3 accessions to different irrigation treatments were somewhat different but with respect to total number of spikelets produced per plant, they all responded in the same way. Different irrigation management schedules may be required for different cultivars for commercial seed production.

IRRIGATION MANAGEMENT OF ALFALFA FOR SEED

1977 ◽  
Vol 57 (3) ◽  
pp. 891-896 ◽  
Author(s):  
K. K. KROGMAN ◽  
E. H. HOBBS
Keyword(s):  
Soil Moisture ◽  
Medicago Sativa ◽  
Seed Production ◽  
Irrigation Management ◽  
Growing Season ◽  
Moisture Stress ◽  
Field Plot ◽  
Southern Alberta ◽  
Medicago Sativa L ◽  
Seed Yields

In field plot experiments conducted in southern Alberta over a 6-yr period, highest seed yields of alfalfa (Medicago sativa L. cv. Beaver) were obtained with one or two irrigations in the first half of the growing season. In outdoor lysimeters protected from rain, moisture stress for more than 8 days before seed ripening severely reduced seed production. Under field conditions, stored soil moisture from irrigation during the vegetative stage of growth plus occasional rain in July and August permitted irrigation of alfalfa for seed to be stopped at the bud to early bloom stage (June to early July).

The spring soil moisture and the summer rainfall in eastern China

2007 ◽  
Vol 52 (23) ◽  
pp. 3310-3312 ◽  
Author(s):  
ZhiYan Zuo ◽  
RenHe Zhang
Keyword(s):  
Soil Moisture ◽  
Eastern China ◽  
Summer Rainfall

Soil moisture assessment based on Sentinel 1/2 and in-situ data: The vineyard case study

2021 ◽  
Author(s):  
Maria Paula Mendes ◽  
Ana Paula Falcão ◽  
Magda Matias ◽  
Rui Gomes
Keyword(s):  
Soil Moisture ◽  
Climate Models ◽  
Root Zone ◽  
Irrigation Management ◽  
Management Strategies ◽  
Winter Period ◽  
Classification Algorithms ◽  
Precipitation Regime ◽  
Terrain Attributes ◽  
Sentinel 2

<p>Vineyards are crops whose production has a major economic impact in the Portuguese economy (~750 million euros) being exported worldwide. As the climate models project a larger variability in precipitation regime, the water requirements of vineyards can change and drip irrigation can be responsible for salt accumulation in the root zone, especially when late autumn and winter precipitation is not enough to leach salts from the soil upper horizons, turning the soil unsuitable for grape production.</p><p>The aim of this work is to present a methodology to map surface soil moisture content (SMC) in a vineyard, (40 hectares) based on the application of two classification algorithms to satellite imagery (Sentinel 1 and Sentinel 2). Two vineyard plots were considered and three field campaigns (December 2017, January 2018 and May 2018) were conducted to measure soil moisture contents (SMC). A geostatistical method was used to estimate the SM class probabilities according to a threshold value, enlarging the training set (i.e., SMC data of the two plots) for the classification algorithms. Sentinel-1 and Sentinel-2 images and terrain attributes fed the classification algorithms. Both methods, Random Forest and Logistic Regression, classified the highest SMC areas, with probabilities above 14%, located close to a stream at the lower altitudes.</p><p>RF performed very well in classifying the topsoil zones with lower SMC during the autumn-winter period (F-measure=0.82).</p><p>This delineation allows the prevention of the occurrence of areas affected by salinization, indicating which areas will need irrigation management strategies to control the salinity, especially under climate change, and the expected increase in droughts.</p>

scholarly journals Planting Materials Seed Systems of Finger Millet, Rice and Taro in Jumla, Kaski and Bara Districts of Nepal

1970 ◽  
Vol 6 ◽  
pp. 10-22 ◽  
Author(s):  
Bimal K Baniya ◽  
Radha K Tiwari ◽  
Pashupati Chaudhary ◽  
Surendra K Shrestha ◽  
Pushpa R Tiwari
Keyword(s):  
Seed Production ◽  
Finger Millet ◽  
Rice Seed ◽  
Seed Selection ◽  
Seed Supply ◽  
Millet Seed ◽  
Seed System ◽  
Rice Seeds ◽  
Planting Materials ◽  
Informal Seed Supply

Formal and informal seed supply systems of rice (Jumla, Bara and Kaski), finger millet and taro(Kaski) were studied in three ecosites of Nepal during 1999-2001 to understand the processes ofseed flow, seed production, seed selection and storage systems. A survey was conducted at 48 to96 households. Informal seed supply was the only system in Jumla and Kaski and formal systemexisted only in Bara. The main sources of seed were farmer's own saved seed (67-91%), seedfrom neighbors and relatives. Exchange of germplasm was the main basis of fulfillment fromother sources. All farmers obtained seed from their own village, while farmers introducedmaterials occasionally from outside village. Most of the farmers followed seed selection beforeor after crop harvest. Rice field selection and plant selection based on a fixed set of criteria wasthe common practice. Non lodged plants with more grain per panicle, bold grains, well-maturedand uniform plants, long panicle, true to type, good looking grains, free from diseases andinsects were the main rice seed selection criteria. All farmers from both sites stored rice seeds bylocal methods in the locally available containers. Mor and Mudkothi are the special strawcontainers to store rice seed in Bara. Dhara is a special mud structure used to store rice seeds inJumla. Finger millet seed supply system was mostly similar to that of rice seed system. Ninetyone percent farmers saved seed for their own use; however, many of them changed finger milletseeds lots or varieties regularly for their particular plot. Ears selection during harvest by setcriteria for seed purpose was the common practice. Farmers stored finger millet seed carefully insmall locally available containers and tried their best to maintain the quality of seed duringdifferent stage of seed production. Taro has diverse planting materials: cormels, corms witheyes, suckers and corm with small cormels. Taro planting materials management is totallyinformal and almost 89% farmers saved these materials for their use and replaced them mostlyafter 3 years. Farmers had fixed criteria of corms and cormels selection for planting purpose andfocus and more on disease free. Storage of planting materials was locally by using localmaterials and methods. Understanding of seed system in various crops helps to developconservation strategy.Key words: Seed flow; seed production; seed selection; seed storage; seed systemDOI: 10.3126/narj.v6i0.3343Nepal Agriculture Research Journal Vol.6 2005 pp.39-48

scholarly journals THE APPLICATIONS GROUPER SEED PRODUCTION TECHNOLOGY TO SUPPORT MARICULTURE DEVELOPMENT

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Suko Ismi
Keyword(s):  
Survival Rate ◽  
Seed Production ◽  
Production Technology ◽  
Larval Rearing ◽  
Application Technology ◽  
Seed Supply ◽  
Tiger Grouper

Application technology for grouper seed production was conducted by dissemination activities, aimed for dissemination technology in several places having aquaculture prospects in order to facilitate seed supply. The research was conducted  in 2012 collaborated with the Department of Fisheries and Maritime Affairs Lamongan Regency and Fisheries Academy  of Sidoarjo. Application technology for grouper seed production was conducted in Tunggu village, Paciran district, Lamongan, East Java. Grouper seeds which maintained were tiger, cantik, and cantang. Seed productions were performed from egg to juvenile with size of ±3.0 cm,in which the eggs  were transported from hatchery in Bali and larval rearing was conducted based on the produced technology. The results showed that survival rate of tiger grouper was 8.3%, cantang grouper was 11,6%, and cantik grouper was 12.4%.  The results showed that R/C ratio was >1, in which the business was profitable. The technology can be applied to the community and grouper seed production  can support aquaculture activities. Keywords: Grouper seed, production, technology, R/C ratio, aquaculture

scholarly journals Impacts of Late-Spring North Eurasian Soil Moisture Variation on Summer Rainfall Anomalies in Northern East Asia

2021 ◽  
Author(s):  
Yinghan Sang ◽  
Hong-Li Ren ◽  
Yi Deng ◽  
Xiaofeng Xu ◽  
Xueli Shi ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Temperature Gradient ◽  
East Asia ◽  
Summer Rainfall ◽  
Low Pressure ◽  
Late Spring ◽  
Boreal Summer ◽  
Pressure Center ◽  
North Eurasia ◽  
The Impact

Abstract This paper reports findings from a diagnostic and modeling analysis that investigates the impact of the late-spring soil moisture anomaly over North Eurasia on the boreal summer rainfall over northern East Asia (NEA). Soil moisture in May in the region from the Kara-Laptev Sea coasts to Central Siberian Plateau is found to be negatively correlated with the summer rainfall from Mongolia to Northeast China. The atmospheric circulation anomalies associated with the anomalously dry soil are characterized by a pressure dipole with the high-pressure center located over North Eurasia and the low-pressure center over NEA, where an anomalous lower-level moisture convergence occurs, favoring rainfall formation. Diagnoses and Modeling experiments demonstrate that the effect of the spring low soil moisture over North Eurasia may persist into the following summer through modulating local surface latent and sensible heat fluxes, increasing low-level air temperature at higher latitudes, and effectively reducing the meridional temperature gradient. The weakened temperature gradient could induce the decreased zonal wind and the generation of a low-pressure center over NEA, associated with a favorable condition of local synoptic activity. The above relationships and mechanisms are vice versa for the prior wetter soil and decreased NEA rainfall. These findings suggest that soil moisture anomalies over North Eurasia may act as a new precursor providing an additional predictability source for better predicting the summer rainfall in NEA.

Artificial seed production of Pangasiid catfish in the Mekong Delta, Vietnam.

2020 ◽  
Author(s):  
Thanh Phuong Nguyen
Keyword(s):  
Seed Production ◽  
Mekong Delta ◽  
Research Programme ◽  
Larval Rearing ◽  
Growth And Survival ◽  
Seed Supply ◽  
Artificial Seed ◽  
Research Findings ◽  
Artificial Seed Production ◽  
Pangasius Bocourti

Abstract The two pangasiid catfish, Pangasius bocourti and P. hypophthalmus, are widely cultured in the Mekong Delta, Vietnam. However, seed supply until recently was dependent on fry and fingerlings caught from the Mekong River. In 1994, a research programme was carried out on artificial seed production of these two species in captive conditions. In 1995, about 30,000 fingerlings were first produced in An Giang and Can Tho provinces and a proper technique of induced breeding, progressive human chorionic gonadotropin (hCG) treatment, was determined. This technique, involving two steps of hCG injections, successfully induced ovulation in 66% of 67 treated females of P. bocourti. Application of this technique to other pangasiid catfish species such as P. conchophilus, P. hypophthalmus, P. mekongensis, and P. larnaudii also resulted in breeding success. Research on larval rearing has also been conducted to improve the growth and survival of pangasiid larvae. Extension of research findings of induced breeding and larval rearing has allowed mass seed production of pangasiid catfish in the Mekong Delta.

Success and failure of sand goby culture.

2020 ◽  
Author(s):  
Van Khanh Pham
Keyword(s):  
Natural Resources ◽  
Seed Production ◽  
Foreign Exchange ◽  
Environmental Conditions ◽  
Production Systems ◽  
Sand Goby ◽  
Export Markets ◽  
Seed Supply ◽  
Wild Seed

Abstract The success in the seed production of the sand goby (Oxyeleotris marmorata) has contributed to the protection of natural resources and the availability of seed for aquaculture. About 30-50 million sand goby fingerlings are produced in hatcheries for domestic and export markets every year. Grow-out production systems of sand goby developed in the 1990s. It helped to increase the incomes of many fish farmers and contributed to the country's foreign exchange earnings. Constraints to hatchery-produced seed for grow-out have resulted in difficulties for sand goby seed producers. Hatchery-produced seed commands a higher price than wild seed and thus is not able to completely replace the natural seed supply. However, wild seed is of uneven size and capture methods are not standardized, resulting in the fish body being easily scratched, leading to disease and mortality. The fish is sensitive to changes in environmental conditions and vulnerable to diseases which are difficult to treat. The market for this species is also limited.

Irrigation management through a coupled energy-water balance and crop growth model driven by remote sensing data

2021 ◽  
Author(s):  
Marco Mancini ◽  
Chiara Corbari ◽  
Imen Ben Charfi ◽  
Ahmad Al Bitar ◽  
Drazen Skokovic ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Water Use ◽  
Irrigation Water ◽  
Crop Yields ◽  
Irrigation Management ◽  
Balance Model ◽  
Soil Parameters ◽  
Area Index ◽  
Landsat 7

<p>The conflicting use of water is becoming more and more evident, also in regions that are traditionally rich in water. With the world’s population projected to increase to 8.5 billion by 2030, the simultaneous growth in income will imply a substantial increase in demand for both water and food. Climate change impacts will further stress the water availability enhancing also its conflictual use. The agricultural sector is the biggest and least efficient water user, accounts for around 24% of total water use in Europe, peaking at 80% in the southern regions.</p><p>This paper shows the implementation of a system for real-time operative irrigation water management at high spatial and temporal able to monitor the crop water needs reducing the irrigation losses and increasing the water use efficiency, according to different agronomic practices supporting different level of water users from irrigation consortia to single farmers. The system couples together satellite (land surface temperature LST and vegetation information) and ground data, with pixel wise hydrological crop soil water energy balance model. In particular, the SAFY (Simple Algorithm for Yield) crop model has been coupled with the pixel wise energy water balance FEST-EWB model, which assimilate satellite LST for its soil parameters calibration. The essence of this coupled modelling is that the SAFY provides the leaf area index (LAI) evolution in time used by the FEST-EWB for evapotranspiration computation while FEST-EWB model provides soil moisture (SM) to SAFY model for computing crop grow for assigned water content.</p><p>The FEST-EWB-SAFY has been firstly calibrated in specific fields of Chiese (maize crop) and Capitanata (tomatoes) where ground measurements of evapotranspiration, soil moisture and crop yields are available, as well as LAI from Sentinel2-Landsat 7 and 8 data. The FEST-EWB-SAFY model has then been validated also on several fields of the RICA farms database in the two Italian consortia, where the economic data are available plus the crop yield. Finally, the modelled maps of LAI have then been validated over the whole Consortium area (Chiese and Capitanata) against satellite data of LAI from Landsat 7 and 8, and Sentinel-2.</p><p>Optimized irrigation volumes are assessed based on a soil moisture thresholds criterion, allowing to reduce the passages over the field capacity threshold reducing the percolation flux with a saving of irrigation volume without affecting evapotranspiration and so that the crop production. The implemented strategy has shown a significative irrigation water saving, also in this area where a traditional careful use of water is assessed.</p><p>The activity is part of the European project RET-SIF (www.retsif.polimi.it).</p>

Sign in / Sign up

Export Citation Format

Share Document