This study hypothesized that hand weeding and herbicide interventions affect weed diversity, abundance, and dominance in wet-seeded direct rice under rainfed conditions. This means that hand weeding alone is not a good option for weed control in direct seeded rice under rainfed conditions.
Conclusion
Both herbicides used with hand weeding had higher weed control costs than hand weeding alone in the second experiment. Self-application could also result in lower yields and higher weed control costs due to repeated manual weeding.
Literature Cited
Quezon City, Metro Manila, Philippines Retrieved from https://psa.gov.ph/content/selected- statistics-agriculture (accessed June 5, 2018). Sanusan S, Polthanee A, Audebert A, Seripong S, Mouret J (2010) Weed suppression in direct-seeded rainfed lowland rice: Effect of cutting dates and timing of fertilizer application.
Introduction
PHOSPHORUS STATUS IN SOILS FORMING IN THE PYROCLAST DEPOSITS FROM THE 1991 PLINIAN
ERUPTION OF MT. PINATUBO, PHILIPPINES
Abstract
FULL PAPER
Phosphorus is typically found in primary magmatic minerals in the form of apatite [Ca5(PO4)3(F,Cl,OH] (Nanzyo et al., 1997) A fresh tephra deposit (< 2 - 64 mm fragmented pyroclast size ) in an existing volcanic soil can act as a new source of P and temporarily relieve soil P limitation (Nanzyo et al., 1997; Engelstad et al., 1974).
Materials and Methods
In volcanic soils, apatite weathering is the main source of plant-available P (Dahlgren et al., 2004; Nanzyo and Yamasaki, 1998) and has been shown to contribute to the rapid regeneration of volcanic ash soils when N is present (Shoji and Takahashi, 2002). ). Pinatubo covered a surface area of about 2000 km2 with about 5 km3 (dense rock equivalent) of dacitic tephra (Melosantos et al.1996; Newhall and Punongbayan, 1996).
Non-cultivated soils
Cultivated soils
Total P (Ptotal, mg kg-1) is the sum of all forms of P in the soil, i.e. organic, inorganic, occluded and plant-available P (Pansu and Gautheyrou, 2006). Pavail in the extract was determined by ICP-AES and expressed in mg kg-1.
Results
The total P content in the MS horizon and the pyroclast layers in the two soil profiles, P3-a and P3-b, are comparable and vary from 500 to 717 mg kg-1. The Pavail content in the MS horizon and the pumice layer in the two soil profiles also fall in the same value range (55 - 72 mg kg-1).
Discussion
In contrast, the Pavail/Ptotal ratio of the BS in the IR-Lahar/a (IR-Lahar/b) profile is higher than (similar to) that of the corresponding MS. Except for IR-Ash soil, BS always exhibits a higher Pret than MS.
Acknowledgment
Assessment of the P status in the pyroclast-affected cultivated and non-cultivated soils 26 years after deposition showed that the Ptotal and Pavail contents in the evolving modern soils are likely high enough to support the plants' P requirement. The generally lower Ptotal and Pavail values in the buried compared to the modern soils, except for IR-Lahar, reflect the gradual loss of P over time due to apatite dissolution during chemical weathering.
SOIL MICROBIAL FUNCTIONAL DIVERSITY IN CONTINUOUSLY FERTILIZED IRRIGATED
Demand for land productivity is expected to increase from agricultural use to meet the increasing demand for food and bioenergy (Ort et al., 2015). To ensure that the soil can cope with external disturbances, a "subterranean revolution" occurs, which determines how the original soil biological system and the diversity of functions work under intensive agroecosystem management (Bender et al., 2016).
LOWLAND RICE ECOSYSTEM
Agricultural land management is one of the most important anthropogenic activities that greatly alters soil characteristics, including physical, chemical and biological properties ( Jangid et al., 2008 ). However, if not managed properly, conventional practices can have adverse environmental consequences that significantly impact the ability of soil microbial communities to respond effectively to any disturbances (Schionning et al., 2004).
Results and Discussion
The functional composition of microbial communities is important for the available energy resources in the environment. The functional composition of microbial communities is important for the available energy resources in the area.
EFFECTS OF RICE HUSK BIOCHAR APPLICATION UNDER DIFFERENT WATER MANAGEMENT
Declining water availability is also exacerbated by watershed degradation (Rola and Franciso, 2004; Rola et al., 2015). To cope with water scarcity, several water saving techniques (WSTs) were developed to save irrigation water for rice cultivation (Bouman et al., 2007).
ON GRAIN YIELD, SOIL PROPERTIES, AND WATER PRODUCTIVITY IN RICE
Effects on soil physical and chemical properties The effect of soil biochar has been widely reported to improve soil quality for crop production (Ding et al., 2016). This is in contrast to the previous study, which showed that soil pH increases after biochar application (Yuan et al., 2011). However, most previous studies have been conducted on acidic soils with a pH lower than the pH of the biochar used (Abrishamkesh et al., 2015).
In one of the preliminary studies (Sto Domingo et al., 2015), it was observed that Azolla has a high content of available iron.
SCREENING AND SELECTION OF DIFFERENT Azolla spp AS POTENTIAL AMELIORANT
In the 2017 dry season, the biomass of Azolla stock was relatively low when planted in acidic and normal soils. The biomass of Azolla spp regardless of accession was significantly (88%) lower than that in normal soil. The results of the four trials showed no significant differences in the effect of Azolla stocks on changes in soil pH and soil salinity.
Biomass of different Azolla stocks as exposed to acidic and normal soils in 2017 DS, 2018 DS, 2019 DS and 2019 WS under greenhouse experimentation.
ROLE OF IMPROVED VARIETIES IN THE PHILIPPINE RICE PRODUCTION
The development and introduction of modern or improved rice varieties have contributed significantly to increasing rice production in the country. Increase in regional rice production was observed in 9 out of 16 provinces in the country (Mataia et al., 2011). National rice production volume in the Philippines in the last decade has shown positive growth (PSA, 2020).
The country's rice production is constantly challenged by land conversions, a growing population and climate change.
CUSTOMIZING AN OVERHEAD SPRINKLER IRRIGATION SYSTEM FOR AEROBIC RICE
A system called 'aerobic rice' has been developed, in which rice is grown in non-pooled and non-saturated soil like an upland crop (Bouman et al., 2007). The target environments for aerobic rice are irrigated lowlands with water deficits and favorable uplands with access to supplemental irrigation (Belder et al., 2005a). It uses less than 50% of the irrigation water required by conventional flooded rice (Bouman et al., 2007).
Flushing, or applying a minimal amount of water just to keep the soil wet, is the most common method of irrigation in aerobic rice production (Belder et al., 2005b).
PRODUCTION
The use of the prototype SIS and farmers' practice of flushing were also compared. Nozzle size, throw radius and wetted area of the sprinkler irrigation system tested in laboratory setup. During crop growth, the Cu from the sprinkler irrigation system varied from 28 to 91% across trials (Figure 4) with an average value of 57%, which was below the minimum acceptable Cu value of 70% for rotor and impact head sprinklers (Mecham). 2004).
As expected, sprinkler irrigation water productivity was significantly higher by 90% than waterflooding due to lower total water use (Figure 7).
Recommendation
The estimated irrigation cost per m2 under sprinkler irrigation system was PhP 8.62 m-2 while PhP 9.98 m-2 under waterflooding. The mean uniformity coefficient of the sprinkler irrigation system varied widely and most values were below the published Cu standard minimum for the influent rotor sprinkler. The difference in terms of grain yield was insignificant although flood water was 18% higher than sprinkler irrigation.
Osman M, Hassan SB, Yusof KW (2014) Effect of low pressure on irrigation uniformity of a fixed sprinkler irrigation system.
UTILIZATION OF RICE STRAW AS FEEDSTOCK FOR THERMOCHEMICAL CONVERSION: EFFECTS OF AGE
In contrast, the call from the environmental side is the generation and use of a huge amount of rice biomass such as rice husk and rice straw. Rice straw is one of the major sources of non-edible biomass in Asia, including the Philippines (Ngo, 2011). (3) North Cotabato – largest rice producer in Mindanao; and (4) Ilocos Norte – represents the province where the rice straw market exists.
They recommended looking for alternative uses of rice straw and finding ways to reduce its cost.
AND SIZE OF STRAW ON GASIFICATION PERFORMANCE
Comparison between means showed that gasification was not significantly affected by rice straw size. As the age of rice straw increased, the hydrogen-to-carbon (H/C) and oxygen-to-carbon (O/C) ratios decreased. The study was also conducted to determine the heating value of producer gas produced from rice straw biomass.
Only the age of the rice straw had a significant effect on the gasification efficiency.
DIVERSITY ASSESSMENT OF THE TRADITIONAL RICE VARIETIES COLLECTED IN NORTHWEST LUZON
The main advantages of traditional rice breeding for rice are the availability of genes that control traits for more efficient nutrient uptake, utilization, and adaptation to environmental stresses such as submergence, salinity, and high temperatures (Azeez et al., 2018). Some novel quantitative trait loci (QTL) from traditional cultivars include the Saltol QTL from Pokkali (Singh et al., 2008) and the Sub1 gene from the traditional rice cultivar FR13A (Mackill et al., 2010), which were successfully introgressed into the modern cultivar. , IR64, and was issued in 2013 as NSIC Rc 194 (Submarino 1). To date, the Genebank at DA-PhilRice in Nueva Ecija has approximately 17,000 germplasm collections (Niones, 2020), most of which have been phenotypically and genetically characterized (Rabara et al., 2014; Caguiat et al., 2017; Niones, 2020). . ).
With the importance of TRVs in modern rice breeding, this article presents the variability of TRVs collected in Northwestern Luzon that are useful and important in the development of new rice varieties.
RESEARCH NOTE
Most TRVs are taller (62%) with longer stems (62%) and more productive roses (55%) than the population average. An equal proportion (43%) of TRVs had a bubble length shorter or longer than the population mean of 26 cm, with an asymmetry value of 0.28 (Table 2). Variations in grain size and shape of collected traditional rice cultivars from northwestern Luzon.
Frequency distribution of the traditional rice varieties for grain length (a), grain width (b) and grain shape (c);
REACTIONS OF WEEDY RICE VARIANTS TO TUNGRO DISEASE AND BACTERIAL LEAF BLIGHT
Average percentage BLB incidence of weedy rice variants and TN1 variety from three consecutive trials, 15 days after inoculation. Mean percentage RTD incidence of weedy rice variants and TN1 variety from three consecutive trials, 15 days after inoculation. Percentage incidence of RTD on weedy rice varieties and TN1 variety from confirmation trial at 15 days after inoculation.
Percentage incidence of BLB on weedy rice varieties and TN1 variety from confirmation trial at 14 days after inoculation.
CALL FOR PUBLICATION
SCOPE
AUTHOR’S GUIDELINES
The desired position for inserting figures and tables should be indicated in the margin of the manuscript text. The text should include the name of the author and the date of publication. Instructions for submitting the entire paper and research note are in numbers 1-5 of the instructions for authors.
The conclusion summarizes the general or most important implications and main points of the current studies.
EDITORIAL POLICY
CALL FOR PAPERS
