Using topsoil translocation from natural wetlands to restore rice field systems

2021 ◽  
Author(s):  
Bruna M. da Silva ◽  
Leonardo F. B. Moreira ◽  
Daiane Vendramin ◽  
Cristina Stenert ◽  
Odete Rocha ◽  
...  
2019 ◽  
Vol 20 (7) ◽  
pp. 98-102
Author(s):  
Zhanar Zhumadilova ◽  
Ibadulla Tautenov ◽  
Karlygash Abdieva ◽  
Yerik Shorabaev ◽  
Amankeldy Sadanov
Keyword(s):  
Aral Sea ◽  

2017 ◽  
Vol 78 (2) ◽  
pp. 224-232 ◽  
Author(s):  
A. S. Rolon ◽  
R. S. Godoy ◽  
L. Maltchik

Abstract Recent studies indicate that rice fields contribute to the conservation of aquatic plants, however, repeated cultivation can reduce the species diversity harbored by rice fields. Repeated tillage, agrochemical application and environmental homogeneity can reduce plant diversity and select for species more tolerant to disturbance. Our hypotheses were: 1) macrophyte richness and biomass decrease with increased rice crop age; and 2) macrophyte species of rice fields are a subsample of natural wetlands and species loss will increase with crop age. We investigated three rice fields of each different ages (old, intermediate and new ones) and three natural intermittent wetlands for this study. Each area was sampled four times throughout the rice cultivation cycle (off-season, initial growth, final growth and post-harvest). Our results showed that the mean macrophyte richness and biomass were similar between rice fields of different ages and lower than that of natural wetlands. Although species composition in the different-aged rice fields was not markedly different, there was nestedness in the rice fields as age increased. In this study, we verified that macrophyte richness and biomass in rice fields was lower than natural wetlands and the species composition was different among wetland types (rice fields and natural wetlands), however our hypothesis that species richness and biomass will decrease with crop age was not confirmed. All rice crops had similar macrophyte assemblage structure (richness, biomass and species composition). However, the another hypothesis tested was confirmed, macrophyte assemblage of rice fields is a subset of natural wetlands and as, the age of a rice field increases, the species that occur in older rice field are subsets of species that occur in younger ones.


Author(s):  
J. Langmore ◽  
M. Isaacson ◽  
J. Wall ◽  
A. V. Crewe

High resolution dark field microscopy is becoming an important tool for the investigation of unstained and specifically stained biological molecules. Of primary consideration to the microscopist is the interpretation of image Intensities and the effects of radiation damage to the specimen. Ignoring inelastic scattering, the image intensity is directly related to the collected elastic scattering cross section, σɳ, which is the product of the total elastic cross section, σ and the eficiency of the microscope system at imaging these electrons, η. The number of potentially bond damaging events resulting from the beam exposure required to reduce the effect of quantum noise in the image to a given level is proportional to 1/η. We wish to compare η in three dark field systems.


2017 ◽  
Vol 94 (3) ◽  
pp. 37-61
Author(s):  
Douglas R. Littlefield

Some histories of California describe nineteenth-century efforts to reclaim the extensive swamplands and shallow lakes in the southern part of California's San Joaquin Valley – then the largest natural wetlands habitat west of the Mississippi River – as a herculean venture to tame a boggy wilderness and turn the region into an agricultural paradise. Yet an 1850s proposition for draining those marshes and lakes primarily was a scheme to improve the state's transportation. Swampland reclamation was a secondary goal. Transport around the time of statehood in 1850 was severely lacking in California. Only a handful of steamboats plied a few of the state's larger rivers, and compared to the eastern United States, roads and railroads were nearly non-existent. Few of these modes of transportation reached into the isolated San Joaquin Valley. As a result, in 1857 the California legislature granted an exclusive franchise to the Tulare Canal and Land Company (sometimes known as the Montgomery franchise, after two of the firm's founders). The company's purpose was to connect navigable canals from the southern San Joaquin Valley to the San Joaquin River, which entered from the Sierra Nevada about half way up the valley. That stream, in turn, joined with San Francisco Bay, and thus the canals would open the entire San Joaquin Valley to world-wide commerce. In exchange for building the canals, the Montgomery franchise could collect tolls for twenty years and sell half the drained swamplands (the other half was to be sold by the state). Land sales were contingent upon the Montgomery franchise reclaiming the marshes. Wetlands in the mid-nineteenth century were not viewed as they are today as fragile wildlife habitats but instead as impediments to advancing American ideals and homesteads across the continent. Moreover, marshy areas were seen as major health menaces, with the prevailing view being that swampy regions’ air carried infectious diseases.


2017 ◽  
Vol 25 (101) ◽  
pp. 402-408
Author(s):  
Boris B., Kobyljanskij ◽  
◽  
Valery V., Kolomiec ◽  
Boris I., Kuznetsov ◽  
Tatyana B., Nikitina ◽  
...  

2017 ◽  
Vol 3 (4) ◽  
pp. 187 ◽  
Author(s):  
Arief Pambudi ◽  
Nita Noriko ◽  
Endah Permata Sari

<p><em>Abstrak -</em><strong> </strong><strong>Produksi padi di Indonesia setiap tahun mengalami peningkatan, namun peningkatan ini belum mampu memenuhi kebutuhan nasional sehingga impor masih harus dilakukan. Salah satu masalah dalam produksi beras adalah penggunaan pupuk berlebih yang tidak hanya meningkatkan biaya produksi, namun juga merusak kondisi tanah. Aplikasi bakteri tanah sebagai Plant <em>Growth Promoting Rhizobacteria</em> (PGPR) dapat menjadi salah satu solusi terhadap masalah ini. Penelitian ini bertujuan untuk mengisolasi bakteri tanah dari 3 lokasi sawah daerah Bekasi, membandingkan keberadaan total bakteri pada ketiga lokasi tersebut,  dan melakukan karakterisasi isolat berdasarkan karakter yang dapat memicu pertumbuhan tanaman. Dari ketiga lokasi, diperoleh total 59 isolat dan 5 diantaranya berpotensi sebagai PGPR karena kemampuan fiksasi Nitrogen, melarutkan Fosfat, katalase positif, dan motil. Dari ketiga lokasi pengambilan sampel, BK1 memiliki jumlah total bakteri terendah karena aplikasi pemupukan dan pestisida berlebih yang ditandai tingginya kadar P total, serta tingginya residu klorpirifos, karbofuran, dan paration. Kondisi fisik tanah BK1 juga didominasi partikel liat yang menyebabkan tanah menjadi lebih padat. Peningkatan jumlah penggunaan pupuk tidak selalu diikuti peningkatan produktivitas tanaman.</strong></p><p> </p><p><strong><em>Kata Kunci</em></strong><strong><em> </em></strong>- <em>Bakteri tanah, Rhizosfer sawah, PGPR, Pupuk Hayati</em></p><p><strong> </strong></p><p><em>Abstract</em><strong> - </strong><strong>Rice production in Indonesia has increased annually, but this increase has not reached national demand,so imports still done. </strong><strong>One of the problems in rice production is the use of excessive fertilizers that not only increase production costs, but also decreased the soil conditions. The application of soil bacteria as Plant Growth Promoting Rhizobacteria (PGPR) can be the one solution to face this problem. The objective of this study was isolate soil bacteria from 3 locations of rice field in Bekasi, compare the total bacteria in the three locations, and characterize isolates based on the character that can promote plant growth. From three locations, a total of 59 isolates were obtained and 5 of them were potential as a PGPRs due to its Nitrogen fixation activity, Phosphate solubilization, positive catalase, and motility. From three sampling sites, BK1 has the lowest TPC value because of excessive  fertilizers and pesticides application which indicated by high total P levels, and also high chlorpyrifos, carbofuran and paration residues. The physical condition of BK1 soil is also dominated by clay particles which causes the soil more solid. Increasing of fertilizer application is not always followed by increased plant productivity.</strong></p><p><strong> </strong></p><p><strong><em>Keywords</em></strong> - <em>Biofertilizer, PGPR, Rice field rhizosphere, Soil Bacteria</em></p>


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