Yield Of Upland Rice Research Articles

Review of Drought Stress and Seed Priming Effects on Upland Rice Yield and Longevity

Unequal plant stand and poor germination are major constraints in seeds under areas which receive erratic and low rainfall. Seed priming has emerged as a crucial strategy to enhance the biochemical, physiological, and ecological resilience of seeds and seedlings. Employing suitable priming methods at different developmental stages can significantly improve drought tolerance in plants. Research indicates that the primary factors leading to seed deterioration are the combined effects of low temperatures and moisture levels, which trigger abnormal biochemical and physiological responses. Seed priming techniques show promise due to their simplicity and adaptability in local agricultural practices. However, one of the challenges associated with primed seeds is their relatively short storage lifespan. This review aims to explore the biochemical, physiological, and molecular aspects of rice seed priming while proposing innovative techniques to extend seed longevity, improve stand establishment, and increase overall yield. Furthermore, understanding the molecular mechanisms underlying seed priming can lead to the development of more effective priming protocols. This could ultimately contribute to sustainable agricultural practices in regions vulnerable to climate variability.

Improvement of growth and nutrient uptake of upland rice grown on degraded acid soil with the application of liquid organic fertilizer

This research aimed to determine the effectiveness of several types of liquid organic fertilizer (LOF) derived from plant waste and the dose of P fertilizer on the growth and yield of upland rice on degraded acid soil. The treatments consisted of two factors. The first factor (A) was several types of LOF consisting of A1 (control), A2 (LOF containing isolates of P-solubilizing bacteria), A3 (LOF-banana waste), and A4 (A2+A3). The second factor (B) was fertilizer doses consisting of B1 (50% of the recommended dose of P fertilizer), B2 (75% of the recommended dose of P fertilizer), and B3 (100% of the recommended dose of P fertilizer). The treatment combinations were arranged in a factorial randomized block design with three replications. The research results showed that applying either LOF-banana waste or the mixture of LOF-banana waste and LOF-containing isolates of P-solubilizing bacteria improved plant height, the number of tillers, and N and P uptake by the plant. The rice grain yields among the treatments were not significantly different, but the highest rice grain yield (139.8 g/pot) was obtained at the treatment of the mixture of LOF-P isolate + LOF-banana waste (A2+A3 treatments). The 75% of the recommended dose of P fertilizer was not significantly different from 100% P fertilizer with LOF on growth and yield upland rice and nutrient uptake by the plant.

Impact of 240 g/L glyphosate IPA on weed control and upland rice (Oryza sativa L.) growth and yield in a no-tillage system

Glyphosate IPA 240 g/L herbicide is known as one of the effective chemical solutions in weed control, especially in no-tillage systems. No-tillage systems offer advantages in upland rice cultivation by reducing soil damage and production costs. However, the main challenge in the application of no-tillage systems is the presence of pre-planting weeds that can compete with plants in the absorption of growth factors such as nutrients, light, and water. This experiment aims to test herbicide doses that effectively suppress weed growth and optimize the growth and yield of upland rice with the no-tillage system. The experiment was conducted from December 2023 to April 2024 at Ciparanje Farm, Faculty of Agriculture, Padjadjaran University, Jatinangor District, Sumedang Regency, West Java Province, Indonesia. The experiment used Randomized Block Design (RBD), consisting of 7 treatments, each repeated four times. The treatments consisted of 5 doses of glyphosate IPA 240 g/L herbicide 2.00, 3.00; 4.00, 5.00; 6.00 L/ha with no-tillage system; manual weeding; and control with perfect tillage system. Experimental results showed that glyphosate IPA 240 g/L herbicide at a dose of 3.00 - 6.00 L/ha with the no-tillage system can be used to replace the perfect tillage system because it can suppress the growth of broadleaf weeds, namely Ageratum conyzoides, Cleome rutidosperma, Mollugo pentaphylla and Synedrela nodiflora, and grass Digitaria ciliaris. No phytotoxicity symptoms were found, and had a favorable effect on rice plant growth regarding population size and tillers. The yield of rice plants with the highest milled dry grain yield was 4.45 t/ha.

Pengaruh Jenis Biochar dan Jarak Tanam Terhadap Pertumbuhan dan Hasil Padi Gogo (Oryza sativa L.)

Upland rice has the potential to be cultivated on land that has limited water. Plant spacing needs to be done as a strategy so that upland rice can absorb light and water optimally. Apart from that, biochar can be used to improve soil properties so that it is suitable for supporting the growth of upland rice plants on dry land. The study aims to examine the response of biochar application and plant spacing on the growth and yield of upland rice. The study was conducted in the experimental garden of the Faculty of Agriculture, Universitas Perjuangan Tasikmalaya at an altitude of 359 meters above sea level. This study used a factorial Randomized Completely Block Design (RCBD). The first factor is a type of biochar consisting of coconut shells and rice husks charcoal. The second factor is the plant spacing consisting of 20 x 20 cm and 30 x 30 cm. The results showed that there was no interaction between the two treatments on the growth and yield of upland rice. The application of biochar had a significant effect on the number of panicles per hill, while plant spacing had a significant effect on the root length, root wet weight, 1.000 seed weight, and yield. The coconut shell was able to increase the number of panicles per hill, while the wider plant spacing caused an increase in root length, root wet weight, 1.000 seed weight, and yield. In general, the application of biochar can improve crop yields, while regulating the plant spacing has the potential to increase the growth and yield of upland rice.

Application of Various Concentrations of Moringa Leaf Liquid Fertilizer (Moringa oleifera L.) to Stimulate Growth and Yield of Upland Rice Under Various Drought Stresses

Upland rice is susceptible to drought stress in crops, especially on marginal lands. The use of moringa leaf liquid fertilizer as a biostimulant that is very rich in important compounds is expected to increase growth andproduction as well as plant tolerance to drought stress. This study aims to determine the appropriate concentrationof moringa leaf extract liquid fertilizer to inhibit the growth and yield of upland rice plants grown under variouslevels of drought stress. This study was arranged in the form of a 2-factor factorial experiment with randomizedcomplate block design Split plot design form. The main plot is the application of moringa leaf extract liquidfertilizer consisting of four concentration levels 0%, 5%, 10%, 15% moringa leaf liquid fertilizer. Subplots (SP)was drought stress consisting of three levels of percentage of Field Capacity, namely 100%, 75%, and 50% FC.There were 12 treatment combinations of two units in one replication, each treatment combination was repeated3 times for a total of 72 experimental units. The experiment of moringa leaf liquid fertilizer concentration gave asignificant effect on the increase of plant height, number of tillers, productive tillers, flag leaf area, number ofgrain per plant, grain weight per plant, and grain production per hectare at several levels of droughtstress.Concentration of 15% Moringa leaf liquid fertilizer gives a better effect in increasing the productivity ofupland rice with an average yield of 1507.03 tons/hectare under moderate stress (75% field capasity), and anaverage yield of 1081.66 tons/hectare under high drought stress (50% field capasity).

Evaluating the effects of the CERES-Rice model to simulate upland rice (Oryza sativa L.) yield under different plant density and nitrogen management strategies in Fogera Plain, Northwest Ethiopia

This study assessed the optimal nitrogen (N) fertilizer rate and planting density for the well-adapted upland rice cultivar NERICA_4 on the Fogera Plain. The primary objective was to evaluate the effects of varied planting densities and N-fertilizer rates on upland rice yield and other agronomic parameters. A two-year field study (2020 and 2021) was conducted at the Fogera Rice Research Field Station, testing nine plant densities (75, 87, and 98; 72, 82, and 91; 70, 79, and 89 plants per m2 and two N rates (115 and 138 kg N ha−1). The Crop Simulation Model Crop Environment Resource Synthesis (CSM-CERES-Rice) within the Decision Support System for Agrotechnology Transfer (DSSAT) framework was calibrated and validated using site-specific weather, soil, crop, and agronomic management data from the experiment. Results on the subsequent RMSE, RMSEn, and d index values during the calibration phase were 0.074 t ha−1, 1.82 %, and 0.86 of grain yield; 0.307 t ha−1, 3.36 %, and 0.87 of by-product yield; 0.489 t ha−1, 3.74 %, and 0.79 of top dry biomass yield; and 0.28, 8.24 %, and 0.63 of leaf area index values, respectively. Whereas results on the corresponding RMSE, RMSEn, and d index values during the evaluation phase were: 0.58 t ha−1, 1.33 %, and 0.90 of grain yield; 0.69 t ha−1, 0.58 %, and 0.99 of by-product yield; 0.678 t ha−1, 4.36 %, and 0.67 of top dry biomass yield; and 0.75, 13.92 %, and 0.74 of leaf area index, respectively. The findings of the long-term simulation showed that a 23 % increase in grain yield was achieved with 138 kg N ha−1 and 87 plants per m2 of planting density, as compared to 115 kg N ha−1 and 75 plants per m2 of plant density. The recommended optimum plant density and N fertilizer rate were 138 kg N ha−1 with PD2 of plant density for upland rice production in the Fogera Plain.

Investigating the dynamics of upland rice (Oryza sativa L.) in rainfed agroecosystems: an in-depth analysis of yield gap and strategic exploration for enhanced production

IntroductionAddressing the global demand for rice production necessitates innovative approaches to enhance upland rice yield in rainfed agroecosystems, considering the challenges posed by increasing population, limited land fertility, low productivity, and water availability.MethodsIn this study, our study investigated the impact of biochar and organic fertilizer on ten promising rice lines (G1 – G10) and two control (G11 – G12) cultivars under rainfed conditions. The experimental design used a split-plot design with four soil amendments as main plots, namely control, organic fertilizer, biochar, and biochar + organic fertilizer and 12 rice genotypes as subplot.ResultsThe absolute attainable yield gaps, differentiating organic and control (GAP1), biochar + organic and control (GAP2), and biochar and control (GAP3), ranged from 1.5 to 3.7 or increased of 91–580%, 0.8 to 3.5 (72–560%), and 0.6 to 2.58 tons/ha (58–472%), respectively. Notably, G2 + organic exhibited the highest positive absolute yield gap, ranging from 1.1 to 5.38 tons/ha, based on the yield gap matrix. Furthermore, genotype main effect plus genotype-environment interaction (GGE) biplot analysis identified G2 as the most promising rice line, displaying superior yield performance for cultivation in biochar and organic amended soils.DiscussionThese findings provide valuable insights for farmers, governments, and stakeholders, offering a roadmap to optimize rainfed areas for rice production, serving as practical guidance to enhance overall rice productivity in rainfed agroecosystems.

Varieties and phosphorus fertilization effects on productivity and profitability of direct-seeded upland rice (Oryza sativa) in Eastern India

A field experiment was conducted during rainy (kharif) season of 2016 at Hazaribag, Jharkhand to study the effect of varieties and phosphorus (P) applications on grain yield and economics of direct-seeded upland rice (Oryza sativa L.). The experiment was laid out in split plot design with three replications, keeping 3 rice varieties, viz. ‘Vandana’, ‘Anjali’ and ‘CR Dhan 40’, in the main plots and 7 different P rates. viz., 0 kg/ha, phosphorus solubilizing bacteria (PSB) + arbuscular mycorrhizal fungi (AMF), 13.2 kg P/ha through single super phosphate (SSP), 13.2 kg P/ha through SSP + PSB + AMF, 26.4 kg P/ha through SSP, 26.4 kg P/ha through SSP + PSB + AMF and 39.6 kg P/ha through SSP in the sub-plots. The results revealed that yield attributes, viz. effective tillers/m2 (312), filled grains/panicle (130), panicle weight (27.9 g), 1,000-grain weight (22.5 g), and grain (3.91 t/ha) and straw yields (6.17 t/ha) were higher in ‘CR Dhan 40’ compared to ‘Anjali’ (259, 115, 2.04 g, 20.4 g, 3.33 t/ha and 5.64 t/ ha respectively) and ‘Vandana’ (252, 108, 1.78 g, 19.9 g, 3.12 t/ha and 5.53 t/ha respectively). Similarly, application of 39.6 kg P/ha through SSP recorded the highest values for yield attributes, grain (4.25 t/ha) and straw yields (6.79 t/ha), and was at par with 26.4 kg P/ha through SSP + PSB + AMF. Net returns and B:C ratio were also recorded the highest in ‘CR Dhan 40’ with 39.6 kg P/ha through SSP, which was at par with 26.4 kg P/ha through SSP + PSB + AMF. Thus, integrated application of 26.4 kg P/ha through SSP along with PSB and AMF in ‘CR Dhan 40’ can enhance grain yield and net returns of direct-seeded upland rice in Jharkhand.

Soil biological quality in rhizosphere, growth, and yield of upland rice grown on acid soil after amended biochar enriched sap of Kappaphycus alvarezii

Abstract. Rakian TC, Kilowasid LMH, Afa LO, Riskyana A, Nurazizah, Wijayanti Y, Bahrun A, Subair I, Rahni NM, Alam S, Sarawa, Karimuna L. 2023. Soil biological quality in rhizosphere, growth, and yield of upland rice grown on acid soil after amended biochar enriched sap of Kappaphycus alvarezii. Biodiversitas 24: 6780-6792. Biological soil quality is essential in evaluating soil management practices using biochar enriched for upland rice growth on acid soil. Therefore, the study aimed to (i) analyze the effect of biochar-enriched sap of Kappaphycus alvarezii (K-sap) on the abundance of Arbuscular Mycorrhizae Fungi (AMF), bacteria, and protozoa in rhizosphere soil, growth, and yield of upland rice, and (ii) the relationship between the abundance of soil biota and the growth and yield components, as well as straw N, P, and K content on acid soil. Four upland rice were grown on acid soil incubated with biochar-enriched sap for two weeks in pots. Nine treatments of the biochar-enriched sap were tested, namely control, 5% biochar-0% K-sap, 5% biochar-5% K-sap, 5% biochar -10% K-sap, 5% biochar-15% K-sap, 7.5% biochar-0% K-sap, 7.5% biochar-5% K-sap, 7.5% biochar-10% K-sap, and 7.5% biochar-15% K-sap. Each treatment was three replicates in a randomized block design. The results demonstrated that the AMF spores quantity decreased while flagellates increased in the soil rhizosphere. The P and K content increased, the N:P decreased, and P:K ratio varied in the straw of the upland rice. Plant height and total spikelets increased, while root dry weight and roots to shoots ratio (R:S) decreased with biochar enriched. The abundance of AMF spores and flagellates correlated positively and negatively with R:S. Furthermore, R:S was negatively correlated with plant height and total spikelets. Plant height and total spikelets showed a positive correlation, while root dry weight and R:S was negatively correlated with K content in shoot tissue. The P and K contents with N:P ratio and N:P with P:K were negatively correlated. In conclusion, biochar-enriched K-sap effectively regulated the activity and composition of soil biota in the rhizosphere, influencing upland rice's growth, yield, and nutrient balance uptake on acid soils.

Effect of Foliar Applied DAP and Nano-DAP on Growth and Yield of Upland Rice (Oryza sativa L.)

The main objectives of the experiment were to evaluate the effect of DAP and nano-DAP along with basal fertilizers on growth and yield of upland rice. The study was conducted in randomized block design with three replications. The experiment was carried out at Instructional Farm, College of Agriculture, Vellayani, Kerala during November 2022 to February 2023. The study consisted of (4×2)+1 treatments with two factors. The first factor was levels of recommended dose of nutrients (N) with four levels (n1 : 100 per cent N and P; n2 : 75 per cent N and P; n3 : 50 per cent N and P; n4 : 25 per cent N and P). Second factor was foliar fertilizers (F), included two levels (f1 : 2 per cent DAP at AT and PI stage; f2 : 0.2 per cent nano-DAP at AT and PI stage). Plant height, tillers per square metre, leaf area per hill, leaf area index, flag leaf area per hill and total dry matter production were significantly higher in full recommended dose of nutrients. Leaf area per hill, leaf area index, leaf area duration and flag leaf area per hill were higher with DAP treatment. Higher value of leaf area per hill, leaf area index, leaf area duration, flag leaf area per hill, total dry matter production, grain and straw yield were recorded in full dose of fertilizer along with DAP treatment. Considering the growth attributing factors and yield, the application of 100 per cent N and P along with 2 per cent DAP application was the best treatment combination.

Fatores climáticos que afetam a produtividade do arroz de terras altas na região central do Brasil

ABSTRACT The upland rice production is primarily concentrated in a vast area of central Brazil. Given the region’s environmental variability, the performance of rice cultivars can differ signifcantly. This study aimed to identify the key climate factors infuencing the upland rice yield in the central region of Brazil, encompassing four states: Goiás, Mato Grosso, Tocantins and Rondônia. A dataset comprising 177 trials involving commonly cultivated and well-adapted upland rice varieties, derived from the Embrapa’s rice breeding dataset, was analyzed. These trials were conducted in randomized blocks, with three replications, from 1996 to 2018. The generalized additive model approach was employed to adjust the non-linear relationships between environmental factors and grain yield, revealing four climatic variables: maximum air temperature throughout the growth cycle, minimum air temperature at panicle initiation, degree-days from emergence to panicle initiation and degree-days throughout the growth cycle. An increase in the maximum air temperature and degree-days throughout the growth cycle tend to decrease rice yield, while an increase in the minimum air temperature at the panicle initiation and degree-days from emergence to panicle initiation tend to increase it.

The Growth and Yield of Upland Rice (Oryza sativa L.) Applied by Rice Husk Zeolite and Potassium Fertilizer

The Growth and Yield of Upland Rice (Oryza sativa L.) Applied by Rice Husk Zeolite and Potassium Fertilizer

Reasonable dry cultivation methods can balance yield and grain quality of rice

Reducing the water consumption of rice production in China without affecting grain yield and quality is an important challenge. The purpose of this study was to explore whether different dry cultivation methods could improve rice quality while balancing yield to maintain sustainable rice production. A japonica upland rice cultivar and a japonica paddy rice cultivar were cultivated in the field with three cultivation methods: plastic film mulching dry cultivation (PFMC), bare dry cultivation (BC), and continuous flooding cultivation (CF) as control. There was no significant difference in upland rice yield between PFMC and BC, and there was also no significant difference in paddy rice yield between PFMC and CF. Compared with CF, the two varieties yield decreased significantly with BC. Dry cultivation, especially PFMC, could decrease active filling period, chalky rice rate, chalkiness, amylose content, gel consistency, breakdown viscosity, ratio of glutelin to prolamin, leaf senescence, and increase water use efficiency, protein components content, setback viscosity, grain Q-enzyme activity and average filling rate. Compared with paddy rice, upland rice had lower yield, shorter active filling period, lower chalkiness grain rate and gel consistency, and higher amylose content, breakdown viscosity, protein components content and average filling rate. Grain Q-enzyme activity and grain filling parameters were closely related to rice quality. Reasonable dry cultivation methods could balance yield and quality, especially improve the nutritional and appearance quality of rice.

Eco-friendly cellulose hydrogels as controlled release fertilizer for enhanced growth and yield of upland rice

The effect of urea-loaded cellulose hydrogel, a controlled-release fertilizer (CRF) on growth and yield of upland rice were investigated in upland rice. As with the initial research, nitrogen (N) treatments were applied as CRF treatments; T2H (30 kg N ha−1), T3H (60 kg N ha−1), T4H (90 kg N ha−1), T5H (120 kg N ha−1) and recommended dose of fertilizer (RDF) at 120 kg N ha−1 RDF (T6U) in split application and T1 (0 N) as control. Results from this study indicated that applying CRF at the optimum N rate, T4H resulted in maximum grain yield, increasing by 71%. The analysis of yield components revealed that higher grain yield in T4H CRF was associated with an increase in panicle number and number of grains per panicle. Maximum grain N uptake of 0.25 g kg−1 was also observed in T4H CRF. In addition, T4H CRF recorded the highest harvest index (HI) and N harvest index (NHI) of 45.5% and 67.9%, respectively. Application of T4H CRF also recorded the highest N use efficiency (NUE) and N agronomic efficiency (NAE), 52.6% and 12.8 kg kg−1, respectively. Observations show that CRF with only 75% N applied (T4H) in soil improved grain yield when compared to CRF with 100% N and 100% RDF in farmers’ conventional split application. This suggested that CRF with a moderate N application might produce the highest potential yield and improved N efficiencies while enhancing crop production and further increase in N supply did not increase yield and N efficiencies. The results suggest that the application of T4H CRF for upland rice would enhance HI, N efficiencies and improve the yield of upland rice. Also, all growth parameters and yield were positively influenced by the application of CRF as a basal dose compared to split application of conventional urea fertilizers.

Compost of peanuts residue and rice straw compost on soil Nitrogen forms and upland rice yield

<p>This study provides an innovation in making compost from rice straw (low quality) mixed with peanut residue (high quality) to improve the quality of rice straw compost. The purpose of this research was to discover the optimum composition of a mixture of peanut residue and straw for mineralization, absorption, and Nitrogen Use Efficiency (NUE) and its effect on upland rice plants. The study was conducted in three stages. The first stage determined the quality of five compost mixtures: C1, C2, C3, C4, and C5. The second phase of testing for cumulative N minerals was performed after 1, 2, 4, and 8 weeks of incubation. The third stage examined the impact of the compost mixture on the growth and yield of upland rice in comparison with two treatments, namely the control and NPK fertilizer. The results showed a similarity in the forms of mineralization, where the cumulative N mineral increased with the addition of peanut residue to the compost mixture. The use of a mixture of peanut residue and rice straw compost increased net mineralization by 37.27% (C5) to 59.48% (C1), N uptake by 49.19% (C5) to 62.95% (C3), and NUE by 15.04% (C4) to 51.48% (C3). A strong relationship was detected between the quality of the compost and the forms of N in the soil, particularly the nitrate content, total N minerals, and N microbial biomass, with correlation coefficients of 0.92, 0.88, and 0.94, respectively. A strong to very strong relationship was detected between N form and N uptake (r = 0.84), plant height (r = 0.79), number of tillers (r = 0.78), yield of rice plants (r = 0.93 (plant total dry weight), and r = 0.76 (grain weight). The optimum N uptake, NUE, and yield of upland rice were shown by C3 treatment of 405.28 mg pot<sup>-1</sup>, 42.21%, and 6.19 tons ha<sup>-1</sup>, respectively.</p>

Effect of one or more microorganisms on the yield components of upland rice under greenhouse conditions

The use of beneficial microorganisms is an important strategy to improve rice production in a sustainable way. The study was carried out to determine the effect of single and combined beneficial microorganism on the development of upland rice. The experiment was performed in greenhouse and arranged in a completely randomized design with 29 treatments and 4 replications. Treatments consisted of rice seeds cultivar BRS A501 CL treated with single and combined multifunctional microorganisms (1 (Serratia marcescens), 2 (Bacillus toyonensis), 3 (Phanerochaete australis), 4 (Trichoderma koningiopsis), 5 (Azospirillum brasilense), 6 (Azospirillum sp.), 7 (Bacillus sp.), 8 to 28 (combination of all these microorganisms in pairs) and 29 (control)). Inoculation of upland rice with sole and combined microorganism on upland rice increased the roots and shoots development, yield components and grain yield of upland rice. The combinations of Bacillus sp. (BRM 63573) and A. brasilense (AbV5), Azospirillum sp. (BRM 63574) + B. toyonensis (BRM 32110) and Phanerochaete australis (BRM 62389) + Serratia marcenscens (BRM 32114) led to improved roots and shoots development; increased number of panicles and grains per pot, 1000 grains weight and grain yield of rice plants. Besides, the combinations allow helped in increased accumulation of nutrients in roots, shoots and grains of rice plants.

Optimizing Nitrogen Fertilization to Enhance Productivity and Profitability of Upland Rice Using CSM-CERES-Rice.

Nitrogen (N) deficiency can limit rice productivity, whereas the over- and underapplication of N results in agronomic and economic losses. Process-based crop models are useful tools and could assist in optimizing N management, enhancing the production efficiency and profitability of upland rice production systems. The study evaluated the ability of CSM-CERES-Rice to determine optimal N fertilization rate for different sowing dates of upland rice. Field experimental data from two growing seasons (2018-2019 and 2019-2020) were used to simulate rice responses to four N fertilization rates (N30, N60, N90 and a control-N0) applied under three different sowing windows (SD1, SD2 and SD3). Cultivar coefficients were calibrated with data from N90 under all sowing windows in both seasons and the remaining treatments were used for model validation. Following model validation, simulations were extended up to N240 to identify the sowing date's specific economic optimum N fertilization rate (EONFR). Results indicated that CSM-CERES-Rice performed well both in calibration and validation, in simulating rice performance under different N fertilization rates. The d-index and nRMSE values for grain yield (0.90 and 16%), aboveground dry matter (0.93 and 13%), harvest index (0.86 and 7%), grain N contents (0.95 and 18%), total crop N uptake (0.97 and 15%) and N use efficiencies (0.94-0.97 and 11-15%) during model validation indicated good agreement between simulated and observed data. Extended simulations indicated that upland rice yield was responsive to N fertilization up to 180 kg N ha-1 (N180), where the yield plateau was observed. Fertilization rates of 140, 170 and 130 kg N ha-1 were identified as the EONFR for SD1, SD2 and SD3, respectively, based on the computed profitability, marginal net returns and N utilization. The model results suggested that N fertilization rate should be adjusted for different sowing windows rather than recommending a uniform N rate across sowing windows. In summary, CSM-CERES-Rice can be used as a decision support tool for determining EONFR for seasonal sowing windows to maximize the productivity and profitability of upland rice production.

Enhancing Upland Rice Growth and Yield with Indigenous Plant Growth-Promoting Rhizobacteria (PGPR) Isolate at N-Fertilizers Dosage

Upland rice farming plays a crucial role in ensuring food security in Indonesia. This study aimed to evaluate the impact of plant growth-promoting rhizobacteria (PGPR) isolates on the growth of upland rice. The bioassay and pot experiments were conducted to select the capable isolates of PGPR and to investigate the effect of the PGPR inoculant on the N fertilizer efficiency and agronomic traits of upland rice. The bacterial isolates were identified through a biochemical analysis and tested under controlled greenhouse conditions. The selected PGPR inoculant was formulated as a liquid biofertilizer (LB). The three capable isolates were obtained to fix nitrogen, produce indole-3-acetic acid (IAA), organic acid, and nitrogenase activity and were identified through a biomolecular analysis as Delftia tsuruhatensis strain D9, Delftia sp. strain MS2As2, and Bacillus sp. The application of the LB into the soil at a dose of 10 L ha−1 and 50 kg ha−1 N resulted in a grain yield of 29.81 g pot−1 and a relative agronomic effectiveness (RAE) value of 235.08%, signifying a significant improvement over the conventional method. Several variables, including the number of grains, number of panicles, root length, 1000-grain weight, population of nitrogen-fixing bacteria, and nitrogen uptake exhibited a strong correlation with the grain yield, accounting for 97.80% of the observed variation. These findings show the enormous potential of PGPR isolates, specifically of Delftia tsuruhatensis strain D9, Delftia sp. strain MS2As2, and Bacillus sp., in significantly enhancing the upland rice output in Indonesia. Furthermore, the use of an LB as a biofertilizer in conjunction with nitrogen fertilization provides a viable and sustainable way to increase yields and enhance the overall sustainability of the region’s upland rice farming systems.

WATER STRESS IN MODERN UPLAND RICE CULTIVARS: A MULTIVARIATE STUDY BETWEEN PHYSIOLOGICAL TRAITS AND YIELD

Water stress negatively affects upland rice production. The objective of this study was to identify physiological traits that could depict yield responses under water stress conditions. Three modern upland rice cultivars (C) (BRS A501 CL, BRS Esmeralda and BRS Serra Dourada) were subjected to three water availability levels (W): Control (100% of the field capacity throughout the growing cycle) and 70 and 40% of the water applied to the control during flowering. Yield, spikelet sterility, and 1000-grain weight were influenced by the water availability level (p < 0.05), whereas for the cultivar, only 1000-grain weight was significant. The W × C interaction was not significant for the analyzed yield components. Multivariate analysis revealed that well-irrigated plants were positively associated with grain yield and gas exchange traits, whereas the 40% water availability level was highly related to spikelet sterility and the crop water stress index. The best-fitted model for grain yield was obtained using photosynthesis, stomatal conductance, and transpiration (R2 = 0.76). Thus, physiological parameters can be used to explain the variations in upland rice yield under water stress.

The effect of biofertilizer on increasing upland rice yield in rainfed rice field in boyolali

The low availability of nutrients is an obstacle to increasing rice productivity in rainfed rice fields. The application of a combination of biofertilizers and inorganic fertilizers was known to increase the efficiency of using inorganic fertilizers. This study aims to determine the effect of biofertilizers on the growth and yield of rice plants in a rainfed rice field. The study was conducted on rainfed rice fields in Banyusri Village, Wonosegoro District, Boyolali Regency from September to December 2013. A total of 6 biofertilizer products were used in this study, namely PR, RC, ST, AGR, BV and GLK. The rice variety used was Situ Patenggang. The study used a randomized block design with 9 treatments and each treatment was repeated 4 times. The nine treatments were: fertilization according to the recommendations of dry soil test device (P1); ½ dose of P1 (P2); P2 + manure (P3); P2 + PR (P4); P2 + RC (P5); P2 + ST (P6); P2+AGR (P7); P2+BV (P8); P2+GLK (P9). Planting using a 2:1 jajar legowo system with a spacing of 20 x 10 x 40 cm was carried out by direct planting of 4-5 seeds per hole. Biofertilizer application is carried out according to the instructions of each product. Parameters observed included: soil chemical status (N, P, K, C-organic, pH, CEC) before the study; plant growth (plant height, number of tillers and number of productive tillers); yield (weight of harvested dry grain and dry milled); and a simple farming analysis was carried out. The results showed that all combinations of biofertilizers with ½ recommended dose were effective in increasing rice yields but they could not match the yield of rice fertilized according to the recommended dose. The combination of fertilization using GLK biofertilizer showed the highest yield compared to other biofertilizers with an advantage of 48.05% compared to ½ recommended dose of fertilization.