Higher Rice Grain Research Articles

Identification of a suitable crop sequence module for integrated farming system of telangana (India) under irrigated situation

A field experiment was conducted for two years (2017-2019) at the College Farm, AICRP on Integrated Farming Systems unit, PJTSAU, Hyderabad (India) to identify the profitable cropping system module for different integrated farming systems under irrigated situation in sandy loam soils of Southern Telangana zone, Telangana (India). Among the ten cropping systems evaluated, sweet corn-vegetable (tomato) system was found more remunerative with B:C ratio 3.54, followed by okra-marigold-beetroot system with B:C ratio of 2.92. Among the ecological cropping systems for improving the soil health, Bt cotton + green gram (1:3)-groundnut cropping system gave significantly higher rice grain equivalent yield (13,687 kg ha-1), however the net returns were high (₹ 1,37,259 ha-1) in pigeon pea + green gram (1:7)-sesame cropping system. Out of the two systems tested to meet the household nutritional security, pigeon pea + maize (1:3)-groundnut system gave higher rice grain equivalent yield (13,772 kg ha-1) with higher net returns (? 1,35,959 ha-1). Within the two fodder crops/cropping systems, fodder maize-lucerne system showed higher B:C ratio (1.64). Fodder systems were more exhaustive than all other cropping systems. However, within two years of experimentation the changes in physicochemical properties and soil fertility status were not significantly affected.

Reduced nitrogen application rate with dense planting improves rice grain yield and nitrogen use efficiency: A case study in east China

Dense planting could be a feasible method for reducing nitrogen (N) application rates without compromising rice grain yield in northeast and central China. It is still unclear whether reduced N application with dense planting (RNDP) can achieve higher rice yield and N use efficiency (NUE) in Jiangsu, east China. Three japonica inbred rice (JI) and three indica hybrid rice (IH) cultivars were grown in a field experiment. Their grain yield, NUE, and related traits were compared under two cultivation treatments: conventional high-yielding practice (CHYP) and RNDP. JI showed similar yields under the two treatments, while IH showed lower yield under RNDP than under CHYP, and the partial factor productivity of N and N use efficiency for grain yield increased (P < 0.05) in both JI and IH under RNDP. Compared with CHYP, RNDP reduced spikelets per panicle but increased panicles per m2 and filled-kernel percentage of JI and IH, and JI’s kernel weight was increased (P < 0.05) under RNDP. Shoot biomass weight and nonstructural carbohydrate (NSC) content in the stem at heading and maturity of JI and IH were reduced under RNDP, while harvest index and NSC remobilization reserve were increased (P < 0.05) under RNDP, especially for JI. Our results suggest that RNDP could achieve a higher rice grain yield and NUE, particularly for JI, a dominant rice cultivar type in Jiangsu. For JI, the increased panicles per m2, sink-filling efficiency, harvest index, and NSC remobilization after heading under RNDP contributed to a grain yield similar to that under CHYP.

Organic weed management in wet-seeded and transplanted aromatic rice

A field experiment was conducted during rainy (Sali) season of 2019 in organic block of Instructional-cum-Research farm of the Assam Agricultural University, Jorhat to study the effect of organic weed management practices on weeds, rice growth, yield attributes and yield of aromatic rice (Oryza sativa L. cv Kola Joha) established by wet-seeding and transplanting. The experiment was laid out in split-plot design with main plots of two rice establishment methods, i.e., direct wet-seeding (WSR), puddled transplanting (PTR) and sub plots of five organic weed management practices, viz. weedy check, hand weeding at 20 and 40 days after transplanting (DAT)/seeding (DAS), weeding with rotary weeder at 20 and 40 DAT/DAS, weeding with cono-weeder at 20 and 40 DAT/DAS and intercropping of Sesbania (Sesbania aculeata L.) and its incorporation at 40 DAT/DAS. The puddled transplanting method of rice establishment resulted significantly higher rice grain yield (1.82 t/ha), decreased weed density and biomass compared to the direct wet-seeding method. The hand weeding twice at 20 and 40 DAT/DAS produced the highest grain yield (2.19 t/ha), maximum weed control efficiency and weed control index. The next best was the intercropping of Sesbania and its incorporation at 40 DAT/DAS (1.69 t/ha), which recorded the highest B:C ratio (2.61) under the puddled transplanting system of rice establishment.

Assessment of productivity, profitability and energy efficiency indices of Rice based vegetable crop sequences under mid-hill conditions of Himachal Pradesh

A field experiment was conducted during 2017-18 at Bhadiarkhar farm, Department of Agronomy, Forages and Grassland Management, CSKHPKV, Palampur to evaluate production potential, economic feasibility, energy relations and effects on soil fertility of eight rice-based cropping sequences. Study of one year of crop cycle revealed that rice-palak-cucumber crop sequence resulted in significantly higher rice grain equivalent yield (16477 kg/ha), profitability (Rs 848.76/ha/day), productivity (63.62 kg/ha/day), net return (Rs 219828/ha) and benefit cost ratio than other crop sequences. Rice-wheat crop sequence was superior over all crop sequences in terms of carbohydrate yield (5146 kg/ha), protein yield (640.6 kg/ha) and energy equivalents (23919 kg/ha). Maximum energy output (280.42×103 MJ/ha) and energy efficiency (10.58) were observed in rice-palak-cucumber sequence. Rice-wheat sequence resulted in highest nitrogen, phosphorus and potassium uptake. Nutrient mining (N, P and K) was recorded after completion of crop cycle. Overall, rice–palak-cucumber system was found to be the most productive, profitable, resource-use efficient and remunerative cropping system under mid-hill conditions of Himachal Pradesh.

Побічна продукція рисівництва – біологічна сировина для альтернативного виробництва енергії

Emphasis is placed on the efficiency of production of alternative types of biofuels by rational selection of species and the intensity of biomass formation of plants of the appropriate chemical composition. It is determined that favorable natural and climatic conditions of the South of Ukraine, the presence of built rice irrigation systems make it possible to obtain high yields of high quality rice grain, while forming significant amounts of by-products in the form of straw, husk, flour, which are a source of solid biofuel.As a result of research of bioenergetic potential of Ukrainian rice varieties it is shown that the highest values of energy yield under the use of by-products (straw and husk) are characterized by Viscount and Premium varieties, which studied to determine the impact of agronomic factors on the formation of rice productivity. straw and husks as sources of bioenergy plant raw materials as solid biofuels.

Breeding of a Rice Variety, &amp;lsquo;Sangbo&amp;rsquo;, with High Head Rice Grain Ratio and Good Ripened Grain Color

No-Bong Park, Un-Sang Yeo, Ji-Yoon Lee, Dong-Soo Park, Jong-Hee Lee, Jun-Hyun Cho, You-Chun Song, Seong-Hwan Oh, Young-Bo Son, and Jae-Ki Chang. Korean J. Breed. Sci. 2020;52:441-7. https://doi.org/10.9787/KJBS.2020.52.4.441

Partial substitution of organic nitrogen with synthetic nitrogen enhances rice yield, grain starch metabolism and related genes expression under the dual cropping system.

Improving grain filling in the presernt farming systems is crucial where grain filling is a concern due to the extreme use of chemical fertilizers (CF). A field experiment was conducted at the experimental station of Guangxi University, China in 2019 to test the hypothesis that cattle manure (CM) and poultry manure (PM) combined with CF could improve rice grain filling rate, yield, biochemical and qualitative attributes. A total of six treatments, i.e., no fertilizer (T1), 100% CF (T2), 60% CM + 40% CF (T3), 30% CM + 70% CF (T4), 60% PM + 40% CF (T5), and 30% PM + 70% CF (T6) were used in this study. Results showed that the combined treatment T6increased starch metabolizing enzymes activity (SMEs), such as ADP-glucose phosphorylase (ADGPase) by 8 and 12%, soluble starch synthase (SSS) by 7 and 10%, granule bound starch synthesis (GBSS) by 7 and 9%, and starch branching enzyme (SBE) by 14 and 21% in the early and late seasons, respectively, compared with T2. Similarly, higher rice grain yield, grain filling rate, starch, and amylose content were also recorded in combined treatments. In terms of seasons, higher activity of SMEs , grain starch, and amylose content was noted in the late-season compared to the early season. The increment in these traits was mainly attributed to a lower temperature in the late season during the grain filling period. Furthermore, our results suggested that an increment in starch accumulation and grain filling rate were mainly associated with the enhanced sink capacity by regulating key enzyme activities involved in Suc-to-starch conversion. In-addition, RT-qPCR analysis showed higher expression levels of AGPS2b, SSS1, GBSS1, and GBSE11b genes, which resultantly increased the activities of SMEs during the grain filling period under combined treatments. Linear regression analysis revealed that the activity of ADGPase, SSS, GBSS, and SBE were highly positively correlated with starch and amylose accumulation. Thus, we concluded that a combination of 30% N from PM or CM with 70% N from CF is a promising option in terms of improving rice grain yield and quality. Our study provides a sustainable fertilizer management strategy to enhance rice grain yield and quality at the lowest environmental cost.

Diversification of suitable alternate cropping system for enhancing productivity, profitability and resource use efficiency in Cauvery delta zone of Tamil Nadu

The field experiment was carried out in two location namely at Tamil Nadu Rice Research Institute, Aduthurai, Thanjavur and Soil and Water Management Research Institute, Thanjavur during 2016 - 2019 under irrigated conditions with an objective of alternate cropping system to get more remuneration. The treatments imposed such as pulse – rice – pulse, maize – rice – pulse and rice – rice – pulse cropping systems in both Aduthurai and Thanjavur. The results revealed that higher rice grain equivalent yield, System productivity, Land use efficiency, Production efficiency and Relative economic efficiency were higher in pulse – rice – pulse and maize – rice – pulse system in Aduthurai and Thanjavur centres respectively. Similarly, the less water requirement was observed in the same systems. Based on the results obtained it is recommended that higher profit could be achieved in pulse – rice - pulse and Maize –rice –pulse systems in Aduthurai and Thanjavur respectively with consuming lesser water requirement.

Impact of 12-year-long rice based organic farming on soil quality in terms of soil physical properties, available micronutrients and rice yield in a typic Ustochrept soil of India

ABSTRACT Long-term use of chemical fertilizers has been known to degrade the various soil physico-chemical properties. Incorporation of crop residues (CR) along with biofertilizers (BF) is an important practice from improving the physico-chemical properties of soil. Laboratory analyses were conducted during 2015 on soil samples collected from an on-going long-term experiment “Nutrient management in rice based organic farming systems,” in progress since 2003. Over the 12 years of study a significant improvement in bulk density, water-holding capacity, aggregate stability, hydraulic conductivity, and soil pH was observed under conjoint application of organics, CR, and BF in farmyard manure (FYM)+CR+BF and VC+CR+BF treatments. The data further delineated maximum soil organic carbon build-up was recorded in the combined application of organic nutrient sources as compared to manures alone treatment. The data further indicated that DTPA extractable copper, zinc, manganese, and iron in soil recorded a significant increase in all the manures applied treatments under rice-wheat-mungbean and rice-wheat cropping systems over the initial level. The integrated use of organics and crop residues in combination with biofertilizers recorded significant higher rice grain and straw yields over the rest of the treatments. Organic manures in combination with crop residues and biofertilizers supported high rice grain yield and straw biomass and sustainable yield index (SYI), with lower values of coefficient of variance. In conclusion, the conjoint application of organics, crop residues, and biofertilizers can enhance not only rice crop yield but also yield stability and sustainability.

Integrated nutrient management in scented rice and its residual effect on pea under paira cropping system

An experiment was conducted to study the effect of integrated nutrient management in scented rice and its residual effect on pea under paira cropping system at Regional Research and Technology Transfer Station (RRTTS), Bhawanipatna, Kalahandi, Odisha during 2015-16 and 2016-17. Twelve treatment combinations comprising of T1 - FYM @ 10 t ha-1 + vermicompost @ 2.5 t ha-1 + neem cake @ 2.5 q ha-1 + Azospirillum @ 5 kg ha-1 + PSM @ 5 kg ha-1, T2 - STBFR (Soil test based fertilizer recommendation 75 : 30 : 20 kg N:P2O5: K2O ha-1), T3 - STBFR + FYM @ 5 t ha-1, T4 - STBFR + Azospirillum @ 5 kg ha-1 + PSM @ 5 kg ha-1, T5 - STBFR + Zn @ 5 kg ha-1, T6- STBFR + S @ 20 kg ha-1, T7- STBFR + Zn @ 5 kg ha-1 + S @ 20 kg ha-1, T8- STBFR + FYM @ 5 t /ha + Zn @ 5 kg ha-1 + S @ 20 kg ha-1, T9 - STBFR + FYM @ 5 t ha-1 + Azospirillum @ 5 kg ha-1 + PSM @ 5 kg ha-1, T10 - STBFR + FYM @ 5 t ha-1 + Azospirillum @ 5kg ha-1+ PSM @ 5kg ha-1 + Zn @ 5 kg ha-1 + S @ 20 kg ha-1, T11 - Farmers practice (only chemical fertilizer @ 40 : 20 : 20 kg N : P2O5 : K2O ha-1), T12 - STBFR + vermicompost @ 2.5 t ha-1 were tried in RBD with three replications. The soil of the experimental site was black cotton type having pH- 6.11 , O.C.- 0.72 %, E.C- 0.004 (dS m-1), available N -175.9 kg ha-1 (low), available P-36.7 kg ha-1 (medium) and available K- 283.6 kg ha-1 (high). Geetanjali was the test variety for rice and Azad Pea-1 for pea. Application of STBFR (75 : 30 : 20 kg N : P2O5 : K2O ha-1) + FYM @ 5 t ha-1 + Azospirillum @ 5 kg ha-1 + PSM @ 5 kg ha-1 + Zn @ 5 kg ha-1 + S @ 20 kg ha-1 (T10) to medium duration aromatic rice (var. Geetanjali) produced higher rice grain yield (4065 kg ha-1) and pea seed yield (1044 kg ha-1) from aromatic rice -pea paira cropping system. However, application of STBFR + FYM @ 5 t ha-1 + Zn @ 5 kg ha-1 + S @ 20 kg ha-1 producing grain yield (3944 kg ha-1) and pea seed yield 977 kg ha-1 is another option. Application of STBFR (75 : 30 : 20 kg N : P2O5 : K2O ha-1) + FYM @ 5 t ha-1 + Azospirillum @ 5 kg ha-1 + PSM @ 5 kg ha-1 + Zn @ 5 kg ha-1 + S @ 20 kg ha-1 (T10) recorded maximum gross return (Rs. 1,26,991 ha-1) , net return (Rs. 80,146 ha-1) and B : C ratio of 2.71. The increase in rice equivalent yield (REY) in this treatment was 51.4% higher than the farmer practice i,e., application of chemical fertilizers alone (40 : 20 : 20 kg N : P2O5 : K2O ha-1).

Wood vinegar and biochar co-application mitigates nitrous oxide and methane emissions from rice paddy soil: A two-year experiment

Both biochar (BC) and wood vinegar (WV) influence the nitrous oxide (N2O) and methane (CH4) emissions from agricultural systems. However, the impacts of BC and WV co-application on rice production, N2O and CH4 emissions are not well documented. We here conducted a two-year soil columns experiment with four treatments: WV (5 t WV ha−1), BC (7.5 t BC ha−1), WV + BC (5 t WV ha−1 +7.5 t BC ha−1) and a control (no treatment). The results showed that BC and WV + BC produced higher rice grain yield than the control by 14.1–15.9% in 2016 and by 4.1–5.2% in 2017, respectively. While WV increased rice grain yield by 11.2% in 2016, it had no significant influence on yield in 2017. Both WV and BC significantly mitigated N2O emissions by 22.4–41.8% in 2016 and 22.4–36.9% in 2017, respectively. Interestingly, WV + BC treatment showed the highest N2O mitigation efficiency, with a 52.9–62.8% mitigations in 2016 and 2017. Furthermore, the co-application of WV and BC significantly mitigated CH4 emissions by 42.6% in 2016 and 35.3% in 2017, respectively, while applying WV or BC alone had no annually-consistent mitigation effect on CH4 emissions. Overall, GWPt of rice growth cycle was most significantly suppressed by WV + BC with a 48.7–56.1% reduction, followed by WV and BC with 20.4–28.0% and 19.7–35.7% reductions, respectively. Consequently, the WV + BC treatment had the highest GHGI mitigation effect, averaging with 56.7% over two consecutive rice growth cycles. In conclusion, co-application of WV and BC is recommended for rice cultivation, which can both improve rice yield and minimize GHG emissions.

Identifying critical limit in soil and plant for determining response of rice (Oryza Sativa L.) to silicon application in periyar vaigai command area of Tamil Nadu, India

A survey was undertaken during 2018 to assess silicon (Si) status of soils and to determine its critical limits in soils and plants. A total of 100 surface soil samples (0–15 cm) were collected from 7 major rice growing soil series of Periyar Vaigai Command (PVC) area of Tamil Nadu, India based on their percent coverage. Plant available Si in soils was extracted by 1 M sodium acetate (pH 4.0) and varied from 4 to 250 mg kg−1. Based on the results of pot culture experiment, the critical limit of Si for grain and straw of rice (Oryza sataiva L.) variety ADT-45) determined was 0.49 and 2.53 percent respectively. Similarly the critical limit of soil Si established was 122 mg kg−1. Based on this critical limit, soils were classified into low (< 122 mg kg−1), medium (122 to 181 mg kg−1) and high (> 181 mg kg−1). Rice plants were highly responded to Si application in soils below the critical limit of 122 mg kg−1 whereas soils with Si above 181 mg kg−1 did not respond. Among the levels of Si, 225 mg kg−1 of Si was found to be the optimal dose in Si deficient soils to get higher rice grain yield.

Distribution of Bacterial Blight Resistance Genes in the Main Cultivars and Application of Xa23 in Rice Breeding.

Bacterial blight (BB) is an important constraint on achieving a high and stable rice grain yield. An increasing number of BB resistance (R) genes have been identified and cloned to increase the available options for rice disease resistance breeding. However, it is necessary to understand the distribution of R genes in rice varieties for rational distribution and breeding. Here, we genotyped five R genes, i.e. Xa4, Xa7, Xa21, Xa23, and Xa27, in seventy main cultivars from Guangdong Province, South China using the corresponding specific markers. Our results showed that 61 varieties carried Xa4, only three varieties carried Xa27, and Xa7, Xa21, or Xa23 was not detected in all tested varieties. Notably, only 33 varieties exhibited resistance to pathotype IV Xoo strains. These results indicate that Xa4 is no longer suitable for widespread use in rice breeding, although Xa4 is widely present in tested varieties. Remarkably, the strongly virulent BB strains of pathotype IX evolved quickly in southern China, and Xa23 was found to effectively confer resistance against the pathotype IX strains. Subsequently, we successfully bred two novel inbred rice varieties as also being restorer lines and two photoperiod- and thermo-sensitive genic male sterility (P/TGMS) lines using the broad-spectrum resistance gene Xa23 through marker-assisted selection (MAS) combined with phenotypic selection. All of the developed lines and derived hybrids exhibited enhanced resistance to BB with excellent yield performance. Our research may potentially facilitate both of the inbred and hybrid rice disease resistance breeding.

Nitrogen effect on weed management in rice in a tropical forest-savanna transition zone of Nigeria

ABSTRACT Weed interference and poor soil fertility in rice (Oryza sativa L.) reduce grain yield and economic returns. Field experiments were, therefore, conducted to evaluate the effect of nitrogen (N) and weed-management using manual weeding (MW), herbicide and their combination in upland rice. Increasing N application rate from 0 to 60 and 60 to 90 kg ha−1 resulted in significant increase in weed density and biomass when weeds were controlled with either two MWs or butachlor applied alone at 2 kg ha-1. However, when weeds were controlled with butachlor plus a MW weed density and biomass remained statistically the same with 0, 60 and 90 kg N ha−1. Increasing N application rate to 90 kg ha−1 significantly increased rice grain yield (5.1 t ha−1), similar to the weed-free check (5.2 t ha−1) when the weeds were controlled by butachlor plus a MW. However, under poor weed management (two MWs (2.8 t ha−1) and butachlor applied alone (2.9 t ha−1)), the response was observed only from 0 to 60 kg N ha−1. Increasing N application from 60 to 90 kg ha−1 in plots with two MWs or butachlor applied alone did not increase rice yield but rather increased weed density and biomass. The results showed that N application at 90 kg ha−1 has the potential to increase weed competition if weeds are not adequately controlled. With adequate weed control using butachlor plus MW, however, application of 90 kg N ha−1 provided higher rice grain yield than 0 and 60 kg N ha−1.

ORGANIC FERTILIZATIONTO INCREASE YIELD OF SOYBEAN VAR. ANJASMORO INTERCROPPED WITH VARIOUS VARIETIES OF RED RICE UNDER AEROBIC IRRIGATION SYSTEM

This study aimed to examine the effect of organic fertilization and red rice varieties on growth and yield of soybean grown together with various red rice varieties under aerobic system irrigation. The pot experiment, carried out in the plastic house of the Faculty of Agriculture, University of Mataram in the Narmada experimental farm, was arranged according to the Completely Randomized Design, with three replications and two treatment factors, namely organic fertilization using bokashi of cattle manure (16 ton/ha) applied at rice planting (P0 = without; P1 = with organic fertilizer), and red rice varieties (V1= AM-G2, V2= AM-G4, V3= AM-G9, V4= AM-G10, V5= Inpari 24, V6= Inpago Unram-1), under aerobic irrigation system through sub-irrigation. Pre-germinated soybean seeds (“Anjasmoro” variety) were relay-planted 18 days after planting rice. The results indicated that organic fertilization only significantly increased weights of dry stover, dry pods and grain yield of soybean, whereas rice varieties only affected dry pod weight, and the interaction effect was significant only on soybean grain yield, with the highest average of 17.77 g/pot (equivalent to 2.84 ton/ha) in soybean relay-planted with organic-fertilized rice of “Inpari 24” variety, which grain yield was the lowest (11.1 g/pot or 1,78 ton/ha), indicating that there were below-ground competitions between rice and soybean grown in one pot. However, in the treatment producing the highest rice grain yield (40.9 g/pot or 6.54 ton/ha), the average soybean grain yield was 13.7 g/pot (or 2.19 ton/ha), which is still quite high (far above the national productivity), so relay-planting soybean with rice crop in aerobic irrigation systems supplied with organic fertilizer is still feasible.

Nutrient Uptake and Soil Fertility Status under Different Cropping Systems for Integrated Farming Systems of Telangana State, India

An Randamised Block Design (RBD) field investigation with ten crop sequences under irrigation with recommended package of practices in sandy loam soils of Southern Telangana Zone (STZ), Telangana was carried out during Kharif, Rabi and summer of 2018-2019 with an objective of the nutrient uptake and soil fertility status under different cropping systems and to assess agro economic benefit. These ten cropping systems were grouped in to five categories viz., pre dominant cropping systems of the zone, ecological cropping systems, household nutritional security giving cropping systems, fodder security giving cropping systems and cropping systems involving high value crops. So that from each category, best cropping system can be identified and can be suggested to different integrated farming systems models. In the context of farming systems, under high value crops such as Okra–Marigold–Beetroot system recorded significantly higher rice grain equivalent yield (36,434 kg ha-1) over other systems. Among the ecological cropping systems for improving soil health, Bt cotton + green gram (1:3) - groundnut cropping system was recorded significantly higher rice grain equivalent yield (14,080 kg ha-1) as compared to pigeon pea + green gram (1:7) – sesame cropping system. Among the household nutritional security giving crops, pigeon pea + maize (1:3) – groundnut system was recorded higher rice grain equivalent yield (13,693 kg ha-1). Within the two fodder crops, fodder maize – lucerne system was resulted in higher rice grain equivalent yield (7,709 kg ha-1). Rice - maize and Bt cotton which were the pre-dominant cropping systems of the region wherein rice – maize system recorded comparatively higher rice grain equivalent yield (11,771 kg ha-1) than Bt cotton. Fodder systems were found to be more exhaustive than all other cropping systems. However, within two years of experimentation the changes in physic-chemical properties and soil fertility status were not significantly affected except organic carbon. Organic carbon was high (0.45 %) in case of pigeon pea + green gram (1:6) - sesame cropping system.

Effect of crop residue and nitrogen levels in yield and yield attributing traits of rice under Rice-Wheat Cropping System

A 3- years (2015, 2016 and 2017) field study was carried out at National Wheat Research Program, Bhirahawa, Rupandehi, Nepal to evaluate the influence of crop residues and nitrogen levels on rice. The experiment was conducted in split plot design with three replications. Main plots were two crop residue levels (with crop residues of 30 cm wheat stubble and without crop residues) and sub plots consisted of seven nitrogen levels (0, 25, 50, 75, 100, 125 and 150 kg N ha-1). Combined analysis of three years data revealed that crop residue levels did not differ significantly in terms of grain yield; however crop residues incorporation increased the rice grain yield slightly. Significant difference was observed with application of different nitrogen levels in grain yield and yield attributing characters viz; tillers m-2, panicle length, number of filled grains per panicle and thousands grain weight. Rice grain yield was found at increasing rate with increased level of nitrogen @ 150 kg ha-1. Application of nitrogen @ 150 kg ha-1 gave highest grain yield of 4831kg ha-1 which was found at par with nitrogen @ 125 kg ha-1 with grain yield of 4722 kg ha-1. Crop residues with nitrogen @ 125 kg ha-1 resulted in 216 kg ha-1 higher rice grain yield than residues removed treatment. The overall conclusion is that an improved crop residue management with 125 kg N ha-1 increases the grain yield of rice in long run.

Conservation Agriculture in rice-mustard cropping system for five years: Impacts on crop productivity, profitability, water-use efficiency, and soil properties

Developing suitable crop rotations and crop establishment practices is an important mechanism that can enhance factor productivity and sustainability of an agro-ecosystem. However, the impact of Conservation Agriculture (CA) on alternate crop rotation of the most-dominant but tillage- and input-intensive rice (Oryza sativa L.)-wheat (Triticum aestivum (L.) emend Fiori & Paol) rotation of the Indo-Gangetic Plains (IGP) of India is not elaborately studied. Hence, we evaluated the effect of CA on crop and water productivity, profitability, and soil carbon status in rice-mustard (Brassica juncea L.) rotation in the North-western IGP of India for five consecutive years. Eight treatments comprising of tillage, crop residue, brown manuring (BM) using Sesbania bispinosa, and summer mungbean [Vigna radiata (L.) Wilczek] (SMB) were adopted in rice - mustard cropping system. The conventional transplanted puddled rice (TPR) - conventional till mustard (CTM) (∼TPR-CTM) rotation resulted in significantly higher rice grain yield than zero till direct-seeded rice (ZTDSR) – ZT mustard (ZTM) system with or without crop residue in all five years. However, in this regard, the CA-based ZT rice – mustard - SMB with residue [ZTDSR-ZTM-ZTSMB (+R)] was comparable with it during first three years, but was inferior to it in 4th and 5th years. The ZTDSR-ZTM-ZTSMB (+R) had overall 10.9 % lower five-year mean rice yield than that in the TPR-CTM system. This CA-based system gave significantly higher mustard grain yield in all the years (except first year), and the five-year mean mustard yield was 30.3 % higher than in the TPR-CTM. Another CA-based double cropping system having ZTDSR + BM – ZTM (+R) was comparable with TPR-CTM in all the years and resulted in 27.6 % higher five-year mean mustard yield than the TPR–CTM practice. The ZTDSR-ZTM-ZTSMB (+R) practice gave 44 % (including SMB) and 8.1 % (excluding SMB) higher system productivity and significantly higher sustainable yield index of the rice-mustard system compared with the TPR-CTM practice. The ZTDSR-ZTM-ZTSMB (+R) practice encountered significantly lower weed density in mustard in all five years than TPR-CTM system. The cost-benefit analysis revealed that this CA practice fetched higher net returns by INR 53,000 and 21,400 ha−1 from the rice-mustard system with and without SMB, respectively over the TPR-CTM system. Again, this ZTDSR -ZTM- ZTSMB (+R) system led to an increase in irrigation water productivity by 27.8 % in rice and 35.1 % in mustard, and the total water (irrigation + rainfall) productivity by 35.7 % in mustard crop compared with the TPR-CTM system (P ≤ 0.05). This CA-based rice-mustard system resulted in significantly higher very labile (∼50.6 %) and labile (∼47.7 %) carbon concentration at 0–5 cm depth of soil compared to the conventional TPR-CTM system. The CA system being productive, profitable, and resource-efficient can be recommended for North-western IGP of India and in similar agro-ecologies of the tropics and sub-tropics. It can be adopted with suitable site-specific refinement in South-Asian countries, where decline in crop productivity and soil health is a consistent pervasive problem due to continuous cereal-cereal rotation.

Amendments to saline-sodic soils showed long-term effects on improving growth and yield of rice (Oryza sativa L.).

BackgroundSaline-sodic soils are widely distributed in arid and semi-arid regions around the world. High levels of salt and sodium inhibit the growth and development of crops. However, there has been limited reports on both osmotic potential in soil solutions (OPss) and characteristics of Na+ and K+ absorption in rice in saline-sodic soils under various amendments application.MethodsA field experiment was conducted between 2009 and 2017 to analyze the influence of amendments addition to saline-sodic soils on rice growth and yield. Rice was grown in the soil with no amendment (CK), with desulfurization gypsum (DG), with sandy soil (SS), with farmyard manure (FM) and with the mixture of above amendments (M). The osmotic potential in soil solution, selective absorption of K+ over Na+ (SA), selective transport of K+ over Na+ (ST), the distribution of K+ and Na+and yield components in rice plants were investigated.ResultsThe results indicated that amendments application have positive effects on rice yield. The M treatment was the best among the tested amendments with the highest rice grain yield. M treatment increased the OPss values significantly to relieve the inhibition of the water uptake by plants. Additionally, the M treatment significantly enhanced K+ concentration and impeded Na+ accumulation in shoots. SA values were reduced while ST values were increased for all amendments. In conclusion, a mixture of desulfurization gypsum, sandy soil and farmyard manure was the best treatment for the improvement of rice growth and yield in the Songnen Plain, northeast China.

Effect of different weed management options on weed flora, rice grain yield and economics in dry direct-seeded rice

The shift in the method of rice establishment from traditional manual transplanting of seedlings to direct seeding has occurred in many Asian countries including India. Weeds are the most important biotic constraint in dry direct-seeded rice (dry-DSR) production. Field experiments were carried out during 2015–16 and 2016–17 at Pandit Jawaharlal Nehru College of Agriculture & Research Institute, Karaikal, and Puducherry UT, India to study the effect of different weed management options on the diverse weed flora, rice grain yield and economics in dry-DSR under unpuddled condition. The grassy weeds dominated the weed flora, with 86.12% relative density of Echinochloa colona (L). Link. The sequential application of pendimethalin and bispyribac-sodium herbicides (1000 fb 25 g/ha) with a manual weeding in 40 days after sowing (DAS) reduced total weed density (14.4/m2) and biomass (37 g/m2), resulted in better rice growth (plant height and tillers/m2), yield parameters (panicle weight and 1000 grain weight) and higher rice grain yield (3.86 t/ha). Negative linear relationship was observed between rice grain yield and total weed biomass at 80 DAS. Uncontrolled weeds caused 68.3% dry-DSR yield loss. Pre-emergence pendimethalin 1.0 kg/ha application integrated with manual weeding with or without bispyribac-sodium application and manual weeding thrice recorded higher B: C ratio in deltaic coastal ecosystem of Karaikal, Puducherry UT.