Aerobic Rice Production Research Articles

Co-fertilization of Silicon and Phosphorus Influences the Dry Matter Accumulation, Grain Yield, Nutrient Uptake, and Nutrient-Use Efficiencies of Aerobic Rice

Rice is known to be a nutrient exhaustive crop and the application of silicon (Si) has been reported for the better utilization of plant nutrients from the soil. Hence, the response of the plant to phosphorus (P) could be enhanced by co-fertilization of Si and P. The present study evaluates the dry matter accumulation, grain yield, nutrients uptake, and nutrient-use efficiency of Si and P application in aerobic rice. Therefore, a field experiment was conducted at ICAR-Indian Agricultural Research Institute, New Delhi, India in a factorial randomized block design, the treatments comprised four levels of Si (0, 40, 80, and 120 kg Si ha–1) and P (0, 30, 60, and 90 kg P2O5 ha–1) application. The results revealed the significant effect of Si and P application on dry matter accumulation, grain yield, and nutrient uptake in aerobic rice. The dry matter accumulation and grain yield of aerobic rice was significantly higher with the combination of 120 kg Si and 90 kg P2O5 ha–1 closely followed by the combination of 80 kg Si and 60 kg P2O5 ha–1. The rate of increase in dry matter accumulation due to different doses of Si and P ranged between 7.6 and 25.6 % over control. A strong positive relationship was observed between different doses of Si and P and concentrations and uptakes of different nutrients, barring zinc. Application of Si and P significantly enhanced the grain concentration of Si, nitrogen, P, and potassium by 25, 16.5, 47, and 25 %, respectively, over control. Overall, the addition of Si and P application in nutrient management could increase the productivity and nutrient use efficiency of aerobic rice.

AVIAN SPECIES COMPOSITION PROFILE AND FEEDING GUILDS UNDER THE AEROBIC RICE FIELD

In Malaysia, the aerobic rice production system is an alternative approach to growing rice in a water-scarce environment. Like irrigated rice, aerobic rice also can sustain a diversity of avian fauna. The current status of birds in the rice fields of Malaysia especially under aerobic rice condition has not been widely researched. Therefore, this study aims to document the richness, diversity and feeding guilds of bird species in aerobic rice cultivation area. Birds were sampled and recorded using four randomly set up mist net at an upscaling aerobic rice plot in Serdang, Selangor during a period of the one month starting from the milky stage of the plant (75 days after emergence) until two weeks after harvest. 139 birds representing 11 species belonging to 7 families were recorded in the aerobic rice plot. The most abundant bird family observed was Estrildidae (80.58%), followed by Hirundinidae (6.47%), and Meropidae and Motacillidae (both recorded 5.04%). Scaly-breasted munia (50.36%) and white-headed munia (28.06%) are the most abundant birds, while other types of munia such as chestnut munia and white-rumped munia are present in small numbers. Munias were the most observed bird species number (36.36%) and therefore can be considered as the main avian pest of aerobic rice. The diversity indices, The Shannon-Wiener Index was 1.43 while The Reciprocal Simpson Index was 2.93. The richness index (The Margalef Index) was 2.03. The Equitability Index was 0.59. In term of feeding guild, most species belong to insectivore (45.45%) and granivore (36.36%) while the rest were piscivore/insectivore and granivore/insectivore. However, the granivore recorded the highest number of individuals (112 or 80.58%) compared to other guilds. Presence of a relatively high diversity of bird species with varieties of feeding guilds indicated that aerobic rice does provide an attractive habitat or foraging site for avian fauna.

Nitrogen and weed management treatments effect on productivity of aerobic rice

A field experiment was conducted to study the effect of three nitrogen levels and weed management practices on grain yield of aerobic rice at Tamil Nadu Rice Research Institute, Aduthurai during Kharif seasons of 2014 and 2015. The main plot treatments comprised of three nitrogen levels (75, 100 and 125 kg/ha N) and sub-plot treatments consisted five weed management treatments, viz. rice + Sesbania (dhaincha) (1:1) + pendimethalin pre-emergence application (PE) at 1.0 kg/ha followed by (fb) one hand weeding at 60 days after sowing (DAS); pendimethalin 1.0 kg/ha PE fb mechanical weeding twice at 20 and 40 DAS; rice + Sesbania (dhaincha) (1:1) + pendimethalin 1.0 kg/ha PE fb 2,4 D Na salt 0.8 kg/ha post-emergence application (PoE); mechanical weeding twice at 20 and 40 DAS and un-weeded control. The Rice + Dhaincha (1:1) + pendimethalin PE fb 2,4 D Na salt PoE recorded the lowest weed density at 20 DAS. At 40 and 60 DAS, pendimethalin PE fb mechanical weeding twice at 20 and 40 DAS recorded lower weed density and biomass during both the years. Among the N levels, application of N at 125 kg/ha resulted in maximum rice plant height, number of tillers/m2, number of panicles/m2, panicle weight and grain yield, during both the years. Pendimethalin PE fb mechanical weeding twice at 20 and 40 DAS resulted in higher rice plant height, number of tillers/m2, number of panicles/m2, panicle weight and grain yield. Application of N at 125 kg/ha along with pendimethalin PE fb mechanical weeding twice at 20 and 40 DAS may be used for effective weed management and higher productivity of aerobic rice.

Aerobic Rice Weed Management Optimization through Agro Techniques O. Sativa L.

One of the most widely grown crops, rice (Oryza sativa L.) is crucial to the world's food supply. Historically, rice fields have been flooded for the primary purpose of weed suppression. However, non-flooded or decreased water management practises used in aerobic rice farming systems have received attention because to their potential advantages, which include water saving and increased resource use efficiency. The lack of floods, a traditional method of weed control, makes weed management in aerobic rice systems very difficult. The purpose of this research is to examine and improve agrotechniques for weed control in aerobic rice production utilising Oryza sativa L as the model species.

Low pH of a High Carbon Gleysol Contributes to Nitrification Inhibition Resulting in Low N2O Soil Emissions and Limited Effectiveness of Nitrification Inhibitors

Nitrous oxide (N2O) is a potent greenhouse gas, and drained tropical/subtropical wetland soils that are high in carbon (C) make a substantial contribution to global anthropogenic N2O emissions. However, we previously reported negligible N2O emissions from an acidic, C-rich Gleysol under aerobic rice (Oryza sativa L.) production in the subtropics despite ample moisture and fertiliser nitrogen (N). In a field experiment, seasonal cumulative N2O emissions in the field following the application of 90 kg ha−1 N as urea were low (0.15 kg N2O-N ha−1·season−1). An incubation study examining the effects of temperature (20 °C, 25 °C and 30 °C) and water-filled pore space (WFPS; 40% vs. 60%) on N transformations showed that incubation temperature had a larger influence on nitrification than WFPS (40% vs. 60%). There was limited nitrification at 20 °C at either WFPS over 30 days, but low concentrations of NO3− (<100 mg kg−1) began to accumulate between 16–23 days at 30 °C and between 23–30 days at 25 °C. Liming soil resulted in nitrification after 10 days, while only minor nitrification was evident in the unlimed soil. The presence of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) with urea delayed nitrification for up to 4 days in the limed soil, suggesting such inhibitors may not provide substantial benefits in high C soils. Our results suggest that a low soil pH contributes to impaired nitrification in the C-rich Gleysol examined, which is associated with low fluxes of N2O in the field. We suggest that soil pH could potentially be manipulated to sustain low rates of nitrification and lower N losses, without compromising crop growth.

Foliar Manganese Supply Enhances Crop Productivity, Net Benefits, and Grain Manganese Accumulation in Direct-Seeded and Puddled Transplanted Rice

Manganese (Mn) deficiency in human nutrition is widespread in the rice–wheat cropping system where cereal grains are the staple food. Agronomic biofortification is an innovative and pragmatic approach to tackle Mn malnutrition. A 2-year field study was conducted to investigate the comparative effect of different Mn application methods: (1) No Mn application, (2) Mn seed coating (2 g kg−1 seed), (3) hydro-priming, (4) Mn seed priming (0.1 M Mn solution), (5) soil application (0.5 kg ha−1), (6) foliar water spray, and (7) foliar Mn spray (0.02 M Mn solution) in improving the productivity, profitability, biofortification and Mn-use efficiencies of rice in puddled transplanted flooded rice (FR) and direct-seeded aerobic rice (AR) production systems. Under AR system, soil physical and biological properties, as well as nutrient dynamics were improved. Averaged across 2 years, improvement in total soil porosity (9%), soil organic carbon (12%), soil microbial biomass carbon (6%), soil microbial biomass nitrogen (3%), total nitrogen (13.6%), available phosphorus (10.98%), and exchangeable potassium (7.1%) were noted in AR system over FR system. Regardless of application methods, Mn nutrition substantially improved the yield and related traits and grain Mn concentration in both production systems. Averaged across 2 years, the increase in grain yield under different Mn application treatments was in the order: foliar application (22%) > seed priming (16%) > soil application (12%) > seed coating (12%). Grain Mn concentration was the highest with foliar application of Mn (27% over control) in both production systems. Moreover, the maximum net benefits and benefit–cost ratio were obtained through Mn-foliar application in both production systems. In conclusion, Mn application by either method improved the productivity, profitability, biofortification and Mn-use efficiencies under FR and AR systems; nevertheless, foliar Mn application performed better for all the studied traits.

Analysis of Asian Rice (Oryza sativa) Genotypes Reveals a New Source of Resistance to the Root-Knot Nematode Meloidogyne javanica and the Root-Lesion Nematode Pratylenchus zeae

The sedentary root-knot nematodes, Meloidogyne spp., and the migratory root-lesion nematodes, Pratylenchus spp., cause significant yield losses, particularly in aerobic and upland rice production systems. Recently, the Asian rice Oryza sativa accessions LD 24 and Khao Pahk Maw (KPM) were shown to be highly resistant to M. graminicola. In this study, we have analyzed the responses and broadness of resistance of these two rice genotypes to another root-knot nematode M. javanica and a root-lesion nematode P. zeae. The penetration as well as post-penetration development and reproduction of nematodes were compared including known susceptible and resistant genotypes. Our results indicate that the genotype KPM confers strong resistance to both M. javanica and P. zeae, while LD 24 was resistant to M. javanica and susceptible to P. zeae. Detailed observations revealed that similar numbers of M. javanica or P. zeae penetrated the resistant and susceptible hosts during early infection stages. However, the development and reproduction of both nematodes were arrested or reduced in resistant genotypes, implying that resistance occurs at the post-penetration stage.

Agronomic and physiological measures to enhance the yield and water productivity of aerobic rice in coastal deltaic region of Karaikal

Agronomic and physiological measures to enhance the yield and water productivity of aerobic rice in coastal deltaic region of Karaikal

Assessing the impacts of climate change on aerobic rice production using the DSSAT-CERES-Rice model

AbstractThis study assessed the impacts of climate change on aerobic rice production using the DSSAT-CERES-Rice model. Actual data observed from four cropping seasons in two sites were used for calibration and validation. Four Representative Concentration Pathway scenarios were used to simulate climate change. The optimum planting windows were simulated across these scenarios. Results showed that DSSAT-CERES-Rice could adequately simulate aerobic rice production. Changes in seasonal rainfall and increases in temperature especially during dry seasons adversely affected aerobic rice production. Reduction of rainfall during the wet seasons favored aerobic rice production. Yield losses are twice as large as gains. Changes in climate could cause yield improvements to decline from 83% to 53% and yield reductions to increase from 150% to 177% towards the end of the 21st century. Selecting the best planting windows could optimize production to avoid huge economic losses. Optimum planting windows were simulated during normal, dry, and wet climate conditions. The derived set of genetic coefficients could be used to assess various aerobic rice farm crop and nutrient management strategies as well as other climate and soil conditions. The long-term projections on aerobic rice production could guide policy and decision-makers on designing long-term climate change adaptation and mitigation plans and programs.

Effect of Seed Priming Practices on Dry Matter Production, Yield and Yield Attributes of Aerobic Rice in Coastal Deltaic Region of Karaiakal

A field experiment was conducted at Karaikal “the tail end of Cauvery Delta Zone” during Navarai season, 2017 (spring) to identify the optimum dates of sowing and seed priming practices on dry matter production (DMP), yield and yield attributes under aerobic rice condition. The treatment variables were replicated thrice and further evaluated in factorial concept of RBD. The treatments consisted of three dates of sowing by weekly interval (started from Feb. 6, 2017) and five seed priming practices viz., water, 1% KCl, 2% moringa leaf extract, 1% pungam leaf extract and 5% cow dung slurry. Considering the seed priming practices, dry matter production, yield and yield attributes of aerobic rice were higher in seed primed with 2% moringa leaf extract which ultimately produced higher grain yield (2256 kg ha-1) followed by the seeds primed with 5% cow dung slurry (1945.1 kg ha-1) and 1% pungam leaf extract (1912.3 kg ha-1), respectively. From the study, it has proved that seed priming @ 2% moringa leaf extract provides higher productivity of aerobic rice during Navarai season at Karaikal.

Growth, productivity and nutrient uptake of aerobic rice (Oryza sativa L.) as influenced by different nutrient management practices

A field experiment was undertaken to study the effect of nutrient management on rice cv. Puspa (IET-17509) during pre-kharif season of 2013 and 2014. The experiment was conducted at Rice Research Station, Bankura with eleven different nutrient management practices i.e., N1 = N, P2O5, K2O @ 60, 30, 30 kg ha-1 (RDF);N2 = RDF + Vermicompost @ 2.5 t ha-1; N3 = RDF + FYM @ 5 t ha-1 ; N4 = FYM @ 5 t ha-1, N5 = Vermicompost @ 2.5 t ha-1 ; N6 = RDF + glyricidia (well decomposed) as green manure @ 3 t ha-1; N7 = RDF + ZnSO4 @ 20 kg ha-1 N8 = RDF + borax @ 2 kg ha-1 ; N9 = RDF + Vermicompost @ 2.5 t ha-1 + ZnSO4 @ 20 kg ha-1 ; N10 = RDF +Vermicompost @ 2.5 t ha-1 + borax @ 2 kg ha-1 ; N11 = RDF + Vermicompost @ 2.5 t ha-1 + ZnSO4 @ 20 kg ha-1 + borax @ 2 kg ha-1 respectively in randomized block design comprising of three replications. The result of experiment revealed that rice plot fertilized with the combination of NPK @ 60:30:30 + VC + ZnSO4@ 20 kg ha-1 + borax @ 2 kg ha-1 recorded the highest grain yield of 4.45 t ha-1 which was 56.69 % higher (2.84 t ha-1) than the FYM treated plot. Organic substitution by FYM and vermicompost (VC) had failed to register the significant impact on growth, yield and nutrient uptake. Nutrient uptake and residual nutrient status was also highest in NPK @ 60:30:30 kg ha-1 + VC @ 2.5 t ha-1 + ZnSO4 @ 20 kg ha-1+ borax @ 2 kg ha-1 fertilized plot.

Environmental fate of bensulfuron-methyl and MCPA in aerobic and anaerobic rice-cropping systems

Bensulfuron-methyl (BM) and 4-chloro-2-methylphenoxyacetic acid (MCPA) are herbicides widely used in rice agroecosystems, and are commonly found in their environments, especially in water resources. The objective of this study was to evaluate the sorption-desorption, leaching, and dissipation of BM and MCPA under aerobic and anaerobic rice cropping conditions. For this purpose, a three-year field experiment was conducted in SW Spain using four management systems: aerobic with sprinkler irrigation and tillage (ST), sprinkler irrigation and no-tillage (SNT), long-term sprinkler irrigation and no-tillage (SNTLT), and anaerobic with flooding and tillage (FT). At the end of the experiment, the partition coefficients (Kd-values) in ST were (2.7, 3.1, and 3.9) and (1.2, 1.5, and 1.9) times significantly lower than the values in {SNT, SNTLT, and FT} for BM and MCPA, respectively. Greater sorption was related to lower values of soil pH for both herbicides and to higher contents in humic acids for BM and fulvic acids for MCPA. The persistence was much longer for BM (t1/2 = 26.9–52.1 days) than for MCPA (t1/2 = 1.54–21.1 days) in all management systems, and both herbicides' dissipation rates were generally greater under aerobic than under anaerobic conditions. The mobility of MCPA was much greater than that of BM. Compared with SNT and SNTLT, leaching losses of the applied BM were greater by 51% for ST, and of the applied MCPA by 55% and 99% for ST and FT, respectively. Therefore, only aerobic rice production with no-tillage in the short- or long-terms could be considered as alternative management strategies with which to reduce water contamination by BM and MCPA in rice-growing environments.

Drip Irrigation in Rice

Photo courtesy of Theivasigamani Parthasarathi. The majority of rice production involves growing the crop in flooded fields, but this method is not necessary for cultivation. While flooding fields is an effective way to reduce weeds and other pests, using fresh water for rice cultivation diverts this limited resource away from other uses. Given the estimate that rice cultivation under flooded conditions uses 30 to 45% of the world's fresh water,1 finding ways to reduce water use to grow rice could have a big impact on access to this resource. Some researchers are evaluating the costs and benefits to growing rice under aerobic conditions where rice is grown in unsaturated soil. Aerobic cultivation relies upon precipitation, and irrigation where needed, and uses less water to grow the crop. Water loss can be reduced even more with the use of drip irrigation systems. Drip irrigation enables the precision application of water and fertilizer and limits evaporation. Using drip irrigation in rice is a relatively new management approach, and the best management practices for these systems are not well understood. In a recent article in Agronomy Journal (https://doi.org/10.2134/agronj2018.01.0002), researchers interested in reducing water use for rice production evaluated conventional aerobic cultivation and drip irrigation systems. The field trials were conducted in 2012 and 2013 at Tamil Nadu Agricultural University, Coimbatore, India. Theivasigamani Parthasarathi, a member of ASA, conducted this research as part of his doctoral degree. The experiment compared conventional aerobic cultivation to a series of drip irrigation treatments. The drip treatments included combinations of three lateral distances (0.6, 0.8, and 1.0 m), two dripper discharge rates (0.6, 1.0 liter per hour), and two irrigation methods (surface and 15-cm subsurface). Rice yield, plant growth, root length, and physiological and leaf gas exchange factors were measured. In general, the use of drip irrigation resulted in 50% water savings and a 29% increase in rice yield compared with aerobic cultivation. Of the 12 drip irrigation treatments, the subsurface drip laid out at a 0.8-m lateral distance with a 1.0 L hsup–1 dripper discharge irrigation system had the best performance in terms of growth, physiology, and rice yield. Drip irrigation appears to increase the length and density of roots, which subsequently increase aboveground growth. Parthasarathi notes there is a two-fold increase in water productivity of aerobic rice under drip irrigation. “This concept could be widely propagated wherever rice is being cultivated under well irrigation sources or where groundwater categories are classified as overexploited and exploited,” he says. “Drip-responsive rice genotypes could be developed, and this is one of the future lines of research in rice variety development.” This could lead to even greater gains in rice yields and further incentivize farmers to change their cultivation system. Demonstrating the potential for high performance using drip irrigation is encouraging for growers considering in investing in new technology and methods to reduce water use. While there are upfront costs to install drip irrigation systems, the technology is compatible with other crops. “The best lateral distance of 0.8 m is suitable to most vegetables and rice crops as well as more economical in system design and cost perspective,” Parthasarathi says. Therefore, growers can not only improve their rice cultivation system, but can utilize the fields for other crops, keeping them in production rotation.

Evaluation of Drip Irrigation System for Water Productivity and Yield of Rice

Core Ideas Drip irrigation improved the aerobic rice yield and water savings by 29 and 50%, respectively. The subsurface drip laid out at 0.8 m lateral distance with 1.0 L per hour dripper discharge irrigation system performed better in rice growth, physiology, and yield. Drip irrigation favored the root oxidizing power, canopy photosynthesis, and dry matter partitioning. There is a twofold increase in water productivity of aerobic rice under drip irrigation system. The use of drip irrigation in upland rice (Oryza sativa L.) cultivation is a contemporary water‐saving strategy. However, inadequate evidence is available related to consequential changes in water productivity on rice yield. The effects of distinctive drip irrigation treatments, namely differences in lateral distances (0.6, 0.8, and 1.0 m), dripper discharge rates (0.6 and 1.0 L per hour, Lph), irrigation methods (surface and subsurface), and the conventional aerobic rice production system (control) on, physiology and water productivity of rice were studied during the summer of 2012 and 2013. Grain yield significantly increased in the subsurface drip irrigation method laid out at 0.8 m lateral distance and in 1.0 Lph discharge rate (5389 kg ha−1) compared with control irrigation method (4181 kg ha−1). This treatment mounts up dry matter partitioning, leaf photosynthesis as well as root oxidizing power. In addition, drip irrigation in aerobic rice production system had twice the water productivity and stimulates longer roots with higher density compared with control irrigation method. The subsurface drip irrigation system with drippers/laterals of 0.8‐m distance with flow rate 1.0 Lph, in aerobic rice production system is a cost‐effective method and had the potential to save water (27.0%) without compromising grain yield in comparison to control irrigation method. This could be the promising technology to be recommended for aerobic rice production system.

Effect of silicon and phosphorus fertilization on growth, productivity and profitability of aerobic rice (Oryza sativa)

A field experiment was conducted at ICAR- Indian Agricultural Research Institute, New Delhi during rainy (kharif) seasons of 2015 and 2016 to study the effect of silicon and phosphorus levels on yield, yield attributes and economics of aerobic rice (Oryza sativa L.). Four levels each of phosphorus (0, 30, 60 and 90 kg P2O5/ha) and silicon (0, 40, 80 and 120 kg Si/ha) were tested in a factorial randomized block design (FRBD) and replicated three times. Growth and yield attributes were significantly higher when phosphorus and silicon were included in the nutrient management of aerobic rice cultivation. Growth, yield, yield attributes and economics were significantly affected by the combined application of silicon and phosphorus. The highest aerobic rice grain yield (5.66 and 5.62 t/ha), net returns (Rupees 92.4×103 /ha and 90.1×103 /ha) and yield attributes were recorded with 90 kg P2O5 /ha during both the years of experimentation. However, it was at par with 60 kg P2O5 /ha during both the years of experimentation. In case of silicon application, highest grain yield (5.53 and 5.65 t/ha), net returns (Rupees 90.7×103 /ha and 92.4×103 /ha) and yield attributes were recorded with 120 kg Si/ha, however, it was at par with 80 kg Si/ha during both the years of experimentation. Therefore, the application of phosphorus and silicon should be adopted for achieving higher productivity and profitability of aerobic rice.

Productivity and Nutrient Uptake of Aerobic Rice as Influenced by Methods of Establishment and Sources of Organic Nutrients

Productivity and Nutrient Uptake of Aerobic Rice as Influenced by Methods of Establishment and Sources of Organic Nutrients

Evaluation of growth and yield performance of aerobic rice under different irrigation intervals in furrow irrigated raised bed (FIRB) system of cultivation

Field experiments were conducted for two years to optimize the suitable raised bed size and irrigation interval for the aerobic rice production system. The treatments consisted of three bed widths and three irrigation intervals daily, once in two days and once in three days). The results showed that aerobic rice in furrow irrigated raised bed (FIRB) of 1.0 m width and 30 cm furrow and schedule the irrigation once in two days gave higher grain and straw yield. Water use efficiency was also higher with this system. So, we can save water along with enhanced yield. Due to the higher yields obtained under raising of aerobic rice under FIRB which accommodated four rows of rice in 1.0 m width of raised bed and irrigating the furrow once in two days gave higher net income and B: C ratio. Hence, for getting better yield and economics of aerobic rice, FIRB with a bed width of 1.0 m and irrigating the furrow once in two days was optimum under irrigated condition.

Mapping Suitable Areas of Central Luzon, Philippines for Aerobic Rice Production Using GIS-Based Land Suitability Analysis

Aerobic rice technology is a production system which involved drought-tolerant rice varieties grown in non-flooded and non-puddled soil in water-scarce areas with appropriate cultural management practices aiming at yield level up to 6.0 tons ha. The study presented suitability maps and spatial data to aerobic rice under different production environments of the Central Luzon Region, Philippines. Simple limitation approach (SLA) was used to derive the overall suitability of aerobic rice production in these areas. Spatial datasets gathered from official sources were likewise used. Of the seven provinces, Nueva Ecija had the biggest potential area of 547,735.80 hectares with 11.49% marked as highly suitable to aerobic rice technology, followed by Bulacan which had a potential area of 255,022.52 hectares with 6.15% marked as highly suitable. Pampanga, Tarlac, Zambales, Aurora and Bataan followed with 6.15 %, 5.88 %, 2.65 %, 1.59 %t and 1.56%, respectively, of their corresponding potential areas suitable for aerobic rice production. The total land area in Central Luzon which was found to be highly suitable for aerobic rice production was 126,959.91 hectares. On the assumption that ART could give an average yield of 4.5 tons per hectare, Central Luzon can supply an additional 571,319.59 metric tons of aerobic rice annually.

Grain quality assessment of direct seeded basmati rice (Oryza sativa L.) under different irrigation regimes in Indian Punjab

Irrigation water, being a scarce resource, requires proper management for good quality aerobic basmati rice production. Field experiments were conducted at Punjab Agricultural University, Ludhiana to evaluate the effect of different irrigation schedules on grain quality of direct seeded basmati rice ‘Pusa Basmati 1121’. Ten treatments comprising of conventional puddled transplanting and nine in direct seeding were tested in randomized block design with four replications. Direct seeding treatments comprised of combination of withholding first irrigation for 6, 9 or 12 days after sowing and follow up irrigations at 30, 50 or 70 mm cummulative pan evaporation (CPE). The milling quality characters of rice like brown, milled and head rice recoveries were highest in conventional transplanting (81.4, 70.9 and 52.4 %, respectively) statistically at par with irrigation schedule of withholding first irrigation for 6 days and subsequent irrigations at 30 mm CPE (80.3, 69.9 and 51.1 %,respectively) significantly better than rest of the treatments.The other quality characters like protein content, minimum cooking time, elongation ratio etc. were also significantly affected by different irrigation schedules at 5 % level of significance. The maximum values of protein content (7.26 %) and minimum cooking time (23.5 minutes) were obtained in irrigation schedule of withholding first irrigation for 6 days and subsequent irrigations at 30 mm CPE whereas elongation ratio was maximum in conventional transplanting (1.87). In Indian Punjab, good quality direct seeded basmati rice can be obtained by holding the first irrigation for 6 days and then irrigating at 30 mm CPE with yields comparable to transplanted rice.

Water productivity, nutrients uptake and quality of aerobic rice as influenced by varieties and iron nutrition

Field experiments were carried out at the research farm of ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India, during Kharif (June–October) seasons of 2011 and 2012 to study the effect of rice varieties and iron fertilization on water productivity, nutrient uptake and quality of aerobic rice. Treatments comprised of two rice varieties (PRH-10 and PS-5) and eight sources and modes of iron fertilization—control (no iron), iron sulphate @ 50 kg/ha + one foliar spray of 2.0% iron sulphate, iron sulphate @ 50 kg/ha + one foliar spray of 0.5% iron chelate, iron sulphate @ 100 kg/ha, two foliar sprays of 2.0% iron sulphate, three foliar sprays of 2.0% iron sulphate, two foliar sprays of 0.5% iron chelate and three foliar sprays of 0.5% iron chelate. Study results indicated that variety PRH-10 had higher concentration and uptake of nitrogen, phosphorus, potassium and iron than PS-5 variety in grain, straw and grain + straw. Three foliar sprays of 2.0% iron sulphate or 0.5% iron chelate favoured higher NPK and iron concentration and uptake in grain and straw of aerobic rice. Grain quality in respect of hulling, milling and head rice recovery was, however, superior in PS-5 than PRH-10. But the protein content was significantly higher in PRH-10 than in PS-5. Application of three foliar sprays of 2% iron sulphate and three foliar sprays of 0.5% iron chelate recorded significantly higher hulling, milling and head rice recovery as compared to control and remained statistically similar with each other. Irrigation and total water productivity was substantially higher in PRH-10 over PS-5. Growing of rice with PRH-10 recorded ~7.7% higher total water productivity as compared to PS-5, across iron fertilizations. Three or two foliar sprays of 2.0% iron sulphate or 0.5% iron chelate favoured higher irrigation and total water productivity of aerobic rice over control (no iron).