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ThesisItem Open Access Performance of transplanted rice under modified conventional system over system of rice intensification(Department of Agronomy, BAU, Sabour, 2020) Kumar, Rahul; Ghosh, MainakThe system of rice intensification (SRI) is not being popularized among the farmers community due to its several complications. The farmers are still believed in conventional transplanted rice for their daily needs. However, there are some specific components of SRI seems to be effective in accelerating the productivity. The research was conducted at Bihar Agricultural University, Sabour during kharif 2019 on transplanted rice in combination with the SRI components to identify the most favorable technique for optimum grain yield. The eight treatments were incorporated as T1 = Conventional PTR (CPTR); T2 = CPTR with 12 days seedling; T3 = CPTR with spacing of 25 cm × 25 cm; T4 = CPTR with single seedling/hill; T5 = CPTR with N-Organic:Inorganic::50:50; T6 = CPTR with Saturation water management; T7 = CPTR with weed management through mechanical rotating hoe; T8 = All component of SRI in randomized block design replicated thrice. The recommended dose of fertilizer was 120:60:40 kg N:P2O5:K2O ha-1 and the general spacing were maintained as 20cm × 15cm. The growth attributes like plant height, leaf area index and plant biomass were found significantly higher under SRI (T8) treatment over the CPTR and in parity with PTR using 12 days old seedlings (T2). The highest yield attributing characters like tillers m-2, panicles m-2 and grains panicle-1 were also recorded higher in SRI (T8) treatment. The grain yield) under SRI (6020 kg ha-1) was found maximum and statistically at par with T2 and significantly higher over CPTR (T1). The lowest grain yield (4413 kg ha-1) was recorded with CPTR with saturation water management. The N, P, K uptake in grain and straw was higher obtained under the SRI treatment (T8). The highest Gross Return (Rs. 122650 ha-1) was recorded under SRI, which was found statistically at par with CPTR with 12 days seedling (Rs. 116281 ha-1) and CPTR with single seedling/hill (Rs. 109330 ha-1). However, the net returns (Rs.78975 ha-1) was recorded maximum with CPTR with 12 days seedling, which was statistically at par with conventional PTR (Rs.70866 ha-1), CPTR with one seedling/hill (Rs.72024 ha-1) and CPTR with spacing of 25 cm × 25 cm (Rs. 68840 ha-1). The net return under SRI showed significantly lower than that of CPTR with 12 days seedlings and it was mainly due to the high cost of cultivation in SRI technique. The return per Rs. invested showed the real scenario of SRI technique where it was found significantly lower than most of the treatments except CPTR with organic manure (T5) and saturation water management (T6). The maximum return per Rs. invested was recorded in CPTR using 12 days old seedlings (2.12) which was found at par with conventional PTR (1.90), CPTR with one seedling/hill (1.93), and CPTR with spacing of 25 cm × 25 cm (1.85). The cost of organic manure was the main burden in SRI technique for high cost of cultivation and low return. The study suggested that though the SRI alone recorded the highest yield but the net return and return per rupee invested were obtained significantly higher in CPTR with 12 days seedling (22% and 53%) when compared to that of SRI alone. Hence it can be concluded that the CPTR with 12 days seedling treatment can be useful for higher rice productivity and economic return.ThesisItem Open Access Effect of different herbicides on complex weed flora in wheat (Triticum aestivum L.)(Department of Agronomy, BAU, Sabour, 2020) Raj, Rishav; SushantA field experiment entitled “Effect of different herbicides on complex weed flora in wheat (Triticum aestivum L.)” was conducted during rabi, season of 2019-20 at the Research farm, Bihar Agricultural College, Sabour, Bhagalpur. The soil of the experimental field was sandy loam in texture, medium in organic carbon (0.50 %), low in available nitrogen (192.45 kg ha-1), medium in available phosphorus (22.64 kg ha-1) and medium in potassium (191.88 kg ha-1) content with neutral pH (7.5). The experiment was laid out in randomized block design with three replications. The treatments consisted of fourteen weed management practices viz, T1: Pendimethalin 30 % EC @ 1000g a.i. ha-1 + Metribuzin 70 % WP @ 210 g a.i. ha- (TM) as PE, T2: Metribuzin 70 % WP @ 210 g a.i. ha-1 as PE, T3: Metribuzin (70 % WP) @ 210 g a.i. ha-1 as PoE, T4: Carfentrazone-ethyl 40 % DF @20 g a.i. ha-1 as PoE, T5: Metsulfuron-methyl 20 % WP @ 4 g a.i. ha-1 as PoE, T6: 2,4-D ethyl ester 38 % EC @ 500 g a.i. ha-1 as PoE, T7: Sulfosulfuron 75 % WG @ 25 g a.i. ha-1 as PoE, T8:Clodinafop-propargyl 15 % + Metsulfuron-methyl 1 % WP (RM) @ 60+4 g a.i. ha-1 as PoE, T9:Sulfosulfuron 75 % + Metsulfuron-methyl 5 % WG (RM) @ 30+2 g a.i. ha-1 as PoE, T10:Carfentrazone-ethyl 20% + Sulfosulfuron 25 % WG (RM) @ 20+25 g a.i. ha-1 as PoE, T11: Clodinafop-propargyl 15 % WP + Metribuzin 70 % WP (TM) @ 60+175 g a.i. ha-1 as PoE, T12: Mesosulfuron-methyl 3 % + Iodosulfuron-methyl-sodium 0.6 % WG (RM) @ 12+2.4 g a.i. ha-1 as PoE,T13: Weed free and T14: Weedy check. The wheat variety HD-2967 was grown on 23th November 2019, and harvesting was done on 5th April, 2020.The weed species which infested the experimental plot were Argemona mexicana, Solanum nigrum, Polygonum plebejum, Anagallis arvensis, Chenopodium album, Melilotus indica, Convolvulus arvensis and Vicia sativa,Phalaris minor, Cynodon dactylon, Fumaria parviflora,Cyperus rotondus, Cyprus iria, Cyprus difformis.Growth parameters viz. plant height, Number of tillers, dry matter production, as well as yield attributes, grain yield and straw yield were maximum under weed free condition (T13), followed by clodinafop-propargyl @ 60 g a.i. ha-1 + metsulfuron-methyl @ 4 g a.i. ha-1 PoE (T8) and Mesosulfuron @ 12 g a.i. ha-1 + Iodosulfuron-methyl-sodium @ 2.4 g a.i. ha-1PoE (T12).Weed free treatment has recorded significantly higher grain (4.49 t ha-1) and straw yield (5.53 t ha-1). The grain yield enhancement of 5.1 % (T8), 7.12 % (T12), 24.4 % (T9) and 43.87 % (weedy check) were observed in weed free treatment. Among the herbicide treatments, carfentrazone-ethyl @ 20 g a.i. ha-1 PoE (T4), sulfosulfuron + metsulfuron-methyl @ 30+2 g a.i. ha-1 PoE (T9) and carfentrazone-ethyl + sulfosulfuron@ 20+25 g a.i. ha-1 PoE (T10) were found phyto-toxic on wheat.Weed free (T13), followed by clodinafop-propargyl @ 60 g a.i. ha-1 + metsulfuron-methyl @ 4 g a.i. ha-1 PoE (T8) and mesosulfuron @ 12 g a.i. ha-1 + iodosulfuron-methyl-sodium @ 2.4 g a.i. ha-1 PoE (T12) were most appropriate for reducing weed population, weed dry matter production, and recorded highest weed control efficiency.Net returns was maximum (Rs.61719 ha-1) under weed free, followed by clodinafop-propargyl @ 60 g a.i. ha-1 + metsulfuron-methyl @ 4 g a.i. ha-1 PoE (T8), mesosulfuron @ 12 g a.i. ha-1 + iodosulfuron-methyl-sodium @ 2.4 g a.i. ha-1PoE (T12), sulfosulfuron @ 30 g a.i. ha-1+ metsulfuron-methyl @ 2 g a.i. ha-1 PoE (T9) and carfentrazone-ethyl @ 20 g a.i. ha-1 + sulfosulfuron @ 25 g a.i. ha-1PoE (T10). Whereas, B:C ratio (1.65) was maximum under clodinafop-propargyl @ 60 g a.i. ha-1 + metsulfuron-methyl @ 4 g a.i. ha-1 PoE (T8), followed by T12 (1.57), T9 (1.45), and T10 (1.32) and weed free (1.48). It can be concluded that application of clodinafop-propargyl @ 60 g a.i. ha-1 + metsulfuron-methyl @ 4 g a.i. ha-1 PoE can be recommended for wheat in enhancing grain yield in terms of better growth, yield attributes and achieving more net returns as well as B: C ratio apart from suppressing the weeds through higher weed control efficiency and lower weed index.ThesisItem Open Access Effect of Bio-fortification through organic and inorganic sources of Zinc & Iron on growth, yield & quality of aromatic rice(Department of Agronomy, BAU, Sabour, 2020) Bharti, Annu; Prasad, ShambhuRice is the staple food crop for more than half of the world’s population which represents a major source of minerals and proteins in developing world and supplies adequate energy in the form of calories and is a good source of thiamine, riboflavin and niacin. But, it lacks other important vitamins such as vitamin A, nutrients like iron and zinc, which are essential to human health (Stalin et al. 2011). Zinc and iron deficiencies are well documented problems in food crops, causing decreased crop yields and nutritional quality also. Deficiency of these elements may be overcomed through genetic biofortification and agronomic fortication. The agronomic fortification is cost effective having easy accessibility and gives rapid results. Through this agronomic approach, bio-fortification of rice with Zn and Fe may be possible by adding micronutrient containing fertilizers to the soil or by foliar spray of these micro-nutrients on the plants or through integration of both the methods by utilizing inorganic or inorganic sources. A field experiment entitled “Effect of Bio-fortification through organic and inorganic sources of Zinc & Iron on growth, yield & quality of aromatic rice” was conducted during kharif season of 2019 at Research Farm, Bihar Agricultural University, Sabour, Bhagalpur to find out the effect of bio-fortification of Zn and Fe on growth parameters, yield attributes, yield, quality and economics of aromatic rice. The experiment was laid out in Randomized Complete Block Design with ten treatments and replicated thrice. The results of the experiment indicated that the treatment T7 (RDF + SA of ZnSO4 @ 25 kg ha -1 + SA of FeSO4 @ 25 kg ha -1) recorded significantly higher values of growth and yield attributes including grain as well as straw yield over control. However, it was statistically at par with treatment T8 (RDF + 2 FS of 0.5 % ZnSO4 & 2 FS of 0.5 % FeS04 each at 25 DAT & 1 week after flowering). Growth parameters viz., Plant height , number of tillers hill-1, leaf area index and dry matter accumulation at harvest was recorded the highest in treatment T7 (108.53 cm, 16.37, 3.29 and 1001.12 g m-2, respectively) which was statistically at par with T8 (108.38 cm, 14.89, 3.28 and 927.60 g m-2 respectively ). In case of yield attributes viz., number of filled grains panicle-1 and test weight was found highest in treatment T7 (113.00 and 17.60 g respectively) which was statistically at par with T8 (107.33 and 17.05 g, respectively). Soil application of ZnSO4 and FeSO4 each @ 25 kg ha-1 along with RDF recorded significantly higher grain and straw yield of 41.30 q ha-1 and 59.05 q ha-1, respectively followed by T8 (Foliar spray of ZnSO4 and FeSO4 each @ 0.5 % at 25 DAT and 1 week after flowering along with RDF) . In quality parameters the treatments were found comparable with each other. However, highest values of hulling percentage (78.43 %), milling percentage (63.74 %), amylose content (25.13 %) and aroma score (2.51) were recorded with treatment T8 (RDF + 2 FS of 0.5 % ZnSO4 & 2 FS of 0.5 % FeS04 each at 25 DAT & 1 week after flowering) while protein content (7.82 %) was found highest with treatment T7 (RDF + SA of ZnSO4 @ 25 kg ha -1 + SA of FeSO4 @ 25 kg ha -1). Effect of bio-fortification through Zn and Fe on economics showed that the gross return (98250 ₹ ha-1), net return (65698 ₹ ha-1) and benefit-cost ratio (2.02) were higher with treatment T7 (RDF + SA of ZnSO4 @ 25 kg ha -1 + SA of FeSO4 @ 25 kg ha -1) and it was found comparable with T8 (RDF + 2 FS of 0.5 % ZnSO4 & 2 FS of 0.5 % FeS04 each at 25 DAT & 1 week after flowering) in case of net return (60174 ₹ ha-1) and benefit-cost ratio (1.90). For getting higher grain yield and net profit as well as better bio-fortification of aromatic rice with Zn & Fe,, soil application of ZnSO4 and FeSO4 each @ 25 kg ha-1 along with RDF may be recommended and foliar application of ZnSO4 and FeSO4 each @ 0.5 % at 25 DAT & 1 week after flowering along with RDF may be recommended as the best alternative.ThesisItem Open Access Evaluation of potassium management strategy for higher productivity in direct seeded rice(Department of Agronomy, BAU, Sabour, 2020) Raj, Manish; Ghosh, MainakThe Direct Seeded Rice (DSR) technique is becoming popular these days due to the low input demanding nature. Declining of soil fertility and exploration of ground water has lead to evolution of an alternative crop production approach i.e. DSR. The DRS requires less water, labour and curtail the greenhouse emission. After nitrogen the potassium (K) is the most uptaking nutrient from the soil solution pool. However, K incorporation is neglected by the farmers which may cause negative imbalance of K in soil solution. Now days, the demand of K fertilizers has significantly increased by several folds to sustain the rice productivity. The research trial was performed on DSR during kharif 2019 at Bihar Agricultural University, Sabour, to study the evaluation of potassium management strategy for higher productivity in direct seeded rice. The experiment was laid out in randomized block design consisting ten treatments replicated thrice. The first treatment was considered as control where K was not applied but N and P were applied as per recommendation. In the next two treatments K was applied @ 40 kg ha-1 K2O as basal (T2) and 40 kg K2O ha-1 in two equal split as basal and at active tillering stage (T3). In the treatment T4 and T5 there was 150% recommended dose of potassium i.e. 60 kg K2O ha-1 as basal and 30 kg each in basal and at active tillering stage, respectively. The potassium dose was further increased up to 200% i.e. 80 kg K2O ha-1 as basal (T6) and equally in two splits as basal and at active tillering stage (T7). The next two treatments were inclusion of biofertilizer KSB (Potassium Solubilizing bacteria) in the seed treatment with 60 kg K2O ha-1 as basal (T8) and in T9 it was 30 kg K2O ha-1 through Muriate of Potash along with 10 kg K2O through vermicompost as basal were applied under KSB treated seed of rice. Here in the experiment the KSB was applied @ 20g kg-1 seed. Treatment T10 was considered as absolutely control where no fertilizer was applied. The growth parameters like number of tillers, leaf area index (LAI), dry matter accumulation and yield attributing components likes number of panicles per m2 and filled grains per panicle were found significantly higher under the application of 60 kg K2O ha-1 in two splits (T5) over the recommended 40 kg K2O ha-1 application as basal (T2). Treatments under the 80 kg K2O ha-1 (T6 and T7) were found statistically similar with the treatments having 60 kg K2O ha-1 in two splits. The grains per panicle against the 60 kg K2O ha-1 in two split (T5) and 60 kg K2O with KSB incorporation (T8) were gained 15.95% and 12% higher over the recommended dose of K i.e. 40 kg K2O ha-1 as basal (T2). The grain yield was recorded maximum in the above mentioned treatments T5 (4647 kg ha-1) and T8 (4653 kg ha-1) which were statistically higher over all the treatment received only 40 Kg K2O ha-1 (T2, T3, and T9). However, further increment of K dose i.e. 80 kg K2O ha-1 (T6 and T7) did not prove superiority over the 60 kg K2O ha-1 and maintained similar economic output with the treatments T5 and T8. The Agronomic K use efficiency (AEK) and the partial factor productivity of applied K (PFPK) were noted higher (40.83% and 33.91%) against 60 kg K2O ha-1 as compared to that of 80 kg K2O ha-1 (Averaged over 60 and 80 kg K2O ha-1). Hence it can be suggested that the increment of potassium dose up to 60 Kg K2O ha-1 in two equal split application as basal and at active tillering stages or the same amount as basal application with KSB inoculation can be useful to maintaining rice productivity under DSR establishment method with increasing K use efficiency and higher profitability.ThesisItem Open Access Performance of irrigated transplanted rice under site specific nitrogen management using leaf colour chart(Department of Agronomy, BAU, Sabour, 2020) Kumari, Chanda; Ghosh, MainakFertilizers have been one of the major factors for continuous increase in rice production since the green revolution era. To produce high grain yield levels, researchers are developing high yield cultivars which need adequate amount of essential nutrients. In rice the N is one of the vital nutrients over the past decades and increasing the N use efficiency is needy issue. In view of sustainability the field investigation was carried out at Agricultural Research Farm, Bihar Agricultural University, Sabour, Bhagalpur, Bihar, India during the Kharif 2019. The experiment was laid out in randomized block design with seven treatments, replicated thrice. Among the seven treatments, the six were LCC based N management (T1-T6) where three LCC thresholds (3.5, 4.0 and 4.5) were fixed in combination with two N levels (25 and 30 kg N ha-1) for top dressing whenever LCC values of rice leaf noted below the fixed threshold. Treatment seven (T7) was considered as control where the N application was omitted. The growth parameters in most of the cases was maximum in treatment (T6) having LCC threshold <4.5 with 30 kg N ha-1 in split under the total N application 150 kg ha-1. The growth parameters under the LCC threshold <4.0 with 25 kg and 30 kg N ha-1 in split and LCC threshold <4.5 with 25 kg N ha-1 in split recorded statistically similar result with the treatment T6 under the maximum N application. The yield attributes in the treatment T5 under the LCC threshold <4.5 with 25 kg N ha-1 (130 kg N ha-1) recorded the highest number of panicles and found statistically at par with LCC threshold <4.0 with 25 kg N ha-1 (T3) and 30 kg N ha-1 (T4) whereas the treatment T6 recorded significantly lower panicle number than that of treatment T4. The maximum grain yield was observed in the treatment (T5) under LCC threshold <4.5 with 25 kg N ha-1in split (4168 kg ha-1) against the total N 130 kg ha-1. Likewise yield attributing characters the treatment T3 under the LCC <4.0 with 25 kg N ha-1 recorded the similar grain yield with treatment (T4) under the LCC <4.0 with 30 kg N ha-1 and treatment (T5) under LCC <4.5 with 25 kg N ha-1with 14.3 and 23.8% reduced rate of N application, respectively. Treatments T3 to T5 were resulted with similar grain yield under different LCC based treatments and among these T3 treatment under lower consumption of N fertilizer (105 kg N ha-1) scored the higher Agronomic N use efficiency, N recovery efficiency, partial factor productivity of applied N and almost similar internal N use efficiency with the treatment T4 and T5. The treatment T5 recorded the highest gross returns (87585 Rs. ha-1) resulted 7.5% and 5.3% higher net returns over the treatments T3 and T4, respectively. The maximum return per Rs. invested (1.42) was also noticed in T5 and here it was 5.6% and 4.2% higher than that of obtained in T3 and T4, respectively. The study resulted that LCC can be a reliable option and cost-effective tool for the small holders which can save the considerable amount of N fertilizer with profitable economic output.ThesisItem Open Access Performance of plant population and fertility level on greenhouse gas emission from transplanted pearl millet.(Department of Agronomy, BAU, Sabour, 2020) Lal, Kanhaiya; Choudhury, Suborna RoyAn experiment was conducted at Agricultural Research Farm, Bihar Agricultural University, Sabour in the year 2019 (kharif season) to study the performance of transplanted pearl millet vis-à-vis greenhouse gas emission, chemical properties of soil and production economics under varying plant population and fertility level. The experiment was laid out in split plot design, replicated thrice with three main plot treatments viz., M1-45 cm x 20 cm, M2-50 cm x 20 cm and M3-50 cm x 25 cm and three sub plot treatments viz., S1-N90P45K45 kg ha-1, S2-N120P60K60 kg ha-1 and S3-N150P75K75 kg ha-1. The results revealed that among varying plant population levels, 45 cm x 20 cm (M1) recorded significantly higher number of tillers hill-1 and dry matter accumulation. While, among fertility levels, N150P75K75 kg ha-1 (S3) produced significantly higher number of tillers hill-1, plant height and dry matter accumulation. Plant population level 45 cm x 20 cm (M1) recorded significantly higher number of ear m-2 (17.32), ear weight (54.38 g), grain yield (35.86 q ha-1), being at par with 50 cm x 20 cm. Amongst various fertility levels, N150P75K75 kg ha-1 (S3) resulted in significantly higher number of ear m-2 (17.55), ear weight (54.27 g), ear length (26.31 cm) and grain yield (35.71 q ha-1) and it was at par with S2. However, CO2 emission was significantly higher in plant population level 45 cm x 20 cm and fertility level N150P75K75kg ha-1at all the growth stages. Besides, N2O emission was significantly higher in plant population level 50 cm x 25 cm and fertility level N150P75K75kg ha-1 at all the stages. The interaction effect of plant population and fertility levels on CO2 emission varied significantly under various treatment combinations at 35 days after transplanting (DAT) and 65 DAT. 45 cm x 20 cm (M1) recorded significantly higher total gross return (₹88428 ha-1), net return (₹ 62943 ha-1) and B:C ratio (2.47) which were at par with 50 cm x 20 cm and fertility level N150P75K75 kg ha-1 gave significantly higher total gross return (₹ 88208 ha-1) and net return (₹ 61467 ha-1) which was at par with S2 (N120P60K60kg ha-1). But the benefit cost ratio was significantly higher in S1 (N90P45K45kg ha-1) which was at par with S2 (N120P60K60kg ha-1) over S3 (N150P75K75kg ha-1). Based on this research, it can be concluded that 45 cm x 20 cm spacing was found to be a good option for pearl millet cultivation in which the growth parameters, yield attributes and yield of pearl millet was recorded maximum. Global Warming Potential (GWP) was also lower under the plant spacing of 45 cm x 20 cm. Although, among fertility levels, N150P75K75 kg ha-1 performed better in growth parameters, yield attributes and yield of pearl millet but N120P60K60 kg ha-1 also produced good yield (at par with N150P75K75 kg ha-1) and lower GWP as compared to N150P75K75 kg ha-1. 45 cm x 20 cm spacing was economically impressive option with higher B:C ratio. On other hand, N90P45K45kg ha-1 had higher B:C ratio and it was at par with N120P60K60 kg ha-1. So, N120P60K60 kg ha-1 might also be considered as a profitable choice. As per this research findings, spacing of 45 cm x 20 cm among various plant population levels and N120P60K60 kg ha-1 among other fertility levels were economically sound, environmentally safe and profitable one. However, to stand up with a specific conclusion and recommendation, the same experiment needs to be re-conducted and should be validated over different agro-climatic zones of Bihar.ThesisItem Open Access Studies on weed control efficacy of chemical herbicides in direct seeded rice(Department of Agronomy, BAU, Sabour, 2020) Kumar, Ajay; Kumar, SanjayA field experiment entitled “Studies on weed control efficacy of chemical herbicides in direct seeded rice” was conducted during kharif season of 2019-20 at Agricultural Research farm of Bihar Agricultural University, Sabour, Bhagalpur (Bihar). The experiment was carried out in split-plot design with three replications. The main plots comprised of four pre-emergence herbicides treatments viz. (PE1): no pre-emergence, (PE2): Pendimethalin (1000 g a.i. ha-1), (PE3): Oxadiargyl (500 g a.i. ha-1) and (PE4): Pretilachlor (500 g a.i. ha-1) while in sub-plots five post-emergence treatments viz. (PoE1): no post-emergence, (PoE2): Bispyribac (25 g a.i. ha-1), (PoE3): Bispyribac (25 g a.i. ha-1) + Pyrazosulfuron (20 g a.i. ha-1), (PoE4): Fenoxoprop (56 g a.i. ha-1) + Ethoxysulfuron (18 g a.i. ha-1) and (PoE5): Fenoxoprop (56 g a.i. ha-1) fb Halosulfuron (67 g a.i. ha-1), were laid out in the experiment which comprised of twenty treatment combinations. The rice variety Rajendra Sweta was sown with 20 cm row to row spacing and 25 kg/ha seed rate. Among the pre-emergence herbicides, significantly lower weed density, weed dry matter and higher weed control efficiency were recorded with the application of Pendimethalin @ 1000 g a.i ha-1. Among post-emergence herbicides significantly lower weed density, weed dry matter and significantly higher weed control efficiency were recorded with Bispyribac @ 25 g a.i. ha-1 + Pyrazosulfuron @ 20 g a.i. ha-1. Interaction effects showed that PE application of Pendimethalin @ 1000 g a.i. ha-1 fb Bispyribac @ 25 g a.i. ha-1 + Pyrazosulfuron @ 20 g a.i. ha-1 (PoE) recorded significantly lower weed density, weed dry matter and significantly higher WCE at most of the stages of observation. Yield, yield attributing characters and growth parameters of direct seeded rice influenced significantly due to different pre and post-emergence herbicides application. Among pre-emergence herbicides significantly highest grain yield, harvest index, effective tillers m-2, panicle length, number of grains panicle-1, 1000 grain weight, plant height, LAI and no. of tillers m-2 were obtained with Pendimethalin 1000 g a.i. ha-1. In case of post-emergence herbicides significantly highest grain yield, total biomass, harvest index, effective tillers m-2, number of grains panicle-1, 1000 grain weight, plant height, LAI and no. of tillers m-2 were observed with Bispyribac @ 25 g a.i. ha-1 + Pyrazosulfuron @ 20 g a.i. ha-1. Interaction effect showed significant effect on grain yield (4.63 t ha-1), effective tillers m-2 (361), LAI and no. of tillers m-2 with Pendimethalin @ 1000 g a.i. ha-1fb Bispyribac @ 25 g a.i. ha-1 + Pyrazosulfuron @ 20 g a.i. ha-1. The economic study of the herbicide management suggested that highest gross return (₹/ha 88,412/-), net return (₹/ha 54,724/-) and B:C ratio (1.62) could be obtained with application of Pendimethalin @ 1000 g a.i. ha-1 as PE fb Bispyribac @ 25 g a.i. ha-1 + Pyrazosulfuron @ 20 g a.i. ha-1 as PoE. Due to herbicide management in both pre and post-emergence resulted in 55% increase in yield and 78 % and 73 % increase in net returns and B:C ratio respectively over no herbicide application. Based on the results obtained from one year study on chemical weed management in DSR, it leads to a conclusion that the application of Pendimethalin @ 1000 g a.i. ha-1 as pre-emergence fb Bispyribac @ 25 g a.i. ha-1 + Pyrazosulfuron @ 20 g a.i. ha-1 as post-emergence could be a better economic and viable option and may be recommended for effective management of weeds in direct seeded rice.ThesisItem Open Access Effect of tillage systems and nitrogen management on the efficacy of decomposers for in-situ crop residue management in rice- wheat cropping system(Department of Agronomy, BAU, Sabour, 2023) Chandini; Sharm, R. P.The Indo-Gangetic Plains' rice-wheat (RW) cropping system has contributed significantly to India's food security. However, because of declining soil health, increasing demand on natural resources, and new climate change issues, the sustainability of this significant cropping system is in jeopardy. Innovations in crop residue management to prevent straw burning should help farmers achieve sustainable production while reducing nutrient and water inputs and risk from climate change. The irrigated RW system's high yields have produced enormous amounts of crop wastes. Straw burning especially of rice is a common practice that depletes nutrients and seriously impairs air quality, endangering human health and safety. For their management, keeping rice residues as surface mulch in wheat crops is a smart choice. Mulching reduces weed pressure while increasing yield, water productivity, and profitability. Studies on recycling rice residue have been found to improve soil health and quality. Since rice residues are a key source of plant nutrients, regular application can reduce the management of fertiliser in the RW system. The present experiment was carried out during the kharif and rabi seasons of 2020 and 2021 using a split-split plot design with two tillage systems as main plot factors: T1: Puddled transplanted rice – conventional tillage wheat (PTR–CTW) and T2: Zero tillage direct seeded rice – zero tillage wheat (ZTDSR–ZTW); four nitrogen management strategies, N1: No Starter Dose of N (SD) + RDF, N2: SD (25 kg N/ha) + (RDF-25 kg N/ha), N3: SD (25 kg N/ha), and N4: SD (5 kg N/ha foliar spray) + RDF, were applied to the sub-plot and three decomposers-D1: Trichoderma, D2: Aspergillus, and D3: Pusa Decomposer were used as sub-subplot treatments. Findings from the study suggests that treatments T2 (ZTDSR-ZTW), N3 (SD (25 kg N/ha) + RDF), and D3 (Pusa decomposer), increased plant growth parameters individually in both the crops during both the year. Among the tillage systems, conventional PTR produced 2.78 % higher yields as compared to ZTDSR however, ZT wheat yields were 12.01 % higher over CTW. The rice equivalent grain yield was 4.7 % higher in ZTDSR–ZTW system as compared to PTR–CTW system. Application of N3 (SD (25 kg N/ha) + RDF) and D3 (Pusa decomposer) resulted in 11.5 % and 6.4 % higher rice equivalent yields over other treatments. Tillage (T1 in rice and T2 in wheat) along with N3 (SD (25 kg N/ha) + RDF) and D3 (Pusa decomposer) recorded significantly higher yield compared to other treatment combinations. Splitting of RDF nitrogen as starter dose and post crop application (N2) resulted in 1 % lower yield in rice and 5.7 % lower yield in wheat over RDF application (N1). The economic analysis in rice showed that puddle transplanting resulted in 9 % higher gross returns and 5.8 % higher net returns whereas, B:C ratio of ZTDSR were observed to be 3.39 % higher as compared to PTR. In wheat, gross returns (11.4 %), net returns (29.6 %) and B:C ratio (25.76 %) recorded significantly higher values in ZT over conventional tillage. It was also found that crop residue retention (ZTDSR–ZTW) significantly improved various soil properties and some important soil parameters added their benefit in enhancing the soil quality in T2 (ZTDSR–ZTW) such as particulate organic carbon, soil available nitrogen, beta-glucosidase and bulk density. Retention of crop residues significantly improved the soil quality index under T2 (0.87) as compared to (0.81) in T1 tillage system where the residues were incorporated. Among the decomposers Pusa Decomposer significantly improved the soil quality index as compared to Aspergillus or Trichoderma. On the basis of two years study conducted it may be concluded that Zero Tillage in rice may not positively impact the rice yields in short term however, ZT was beneficial for wheat and helped improve the system rice equivalent yields. Moreover, it was found that crop residue retention was less resource intensive as compared to residue incorporation and helped in improving the soil quality sustainably as compared to crop residue incorporation. Additional application of nitrogen as starter dose helped in increasing the crop yields in combination of application of decomposers. Splitting the recommended dose of fertilizer (RDF) as starter dose for residue decomposition and remaining RDF as post crop establishment negatively impacted the crop yields. Combination of appropriate tillage and nitrogen management along with application of suitable decomposers can sustainably increase the crop yields while reducing the production costs as well as improve the soil health over time.ThesisItem Open Access Effect of potassium management under different establishment methods on productivity of rice (Oryza sativa L.)-wheat (Triticum aestivum L.) cropping system(Department of Agronomy, BAU, Sabour, 2023) Raj, Prithvi; Sharma, R. P.The rice (Oryza sativa L.) -wheat (Triticum aestivum L.) cropping system, being the most extensive and productive system, occupies 13.5 M ha land and produces staple grain supply to millions of people in South Asia (Singh et al., 2017). Rice-wheat cropping system is a cornerstone of India’s food and nutritional securities, with 75 % contribution to the national food chain. Direct seeded rice and zero tillage wheat practices are becoming popular in this cropping system as sustainable agricultural management practices due to unavailability of water, labour scarcity and higher production cost in conventional system (PTR-CTW). Potassium is an important primary nutrient and is required for crop growth and productivity. In continuous cropping systems without application of potassium fertilizer, soil available K rapidly depletes due to higher uptake by crop as well as due to removal of crop residue. The addition of about 8.15 to 8.97 Mg ha−1 of rice straw can add K averaged 197-221 kg ha−1 year−1 (Sharma et al., 2021). Some microorganism has been reported to play a key role in the natural potassium cycle like Pseudomonas, Bacillus mucilaginosus and Bacillus edaphicus have been found to release potassium in an accessible form from potassium-bearing minerals in soils. These help to dissolve potassium from insoluble K-bearing minerals such as micas, illite, and orthoclases, by excreting organic acids which either directly dissolved rock K or chelated silicon ions to bring K into the solution. Thus, keeping in view the above consideration present study was formulated to find out the effectiveness of crop establishment, residue retention, split application of potassium and use of KSB on growth and productivity of rice crop, their residual effect on succeeding wheat crop and fertility status of soil. A field experiment was conducted during the period of 2019-2021 at Bihar Agricultural University, Sabour, Bhagalpur, Bihar to identify the “effect of potassium management under different establishment methods on productivity of rice-wheat cropping system”. The experiment was conducted in split plot design with three main plots i.e., M1: puddled transplanting rice (PTR) followed by conventional-till wheat (PTR/CTW), M2: PTR followed by zero-till wheat with residue (PTR/ZTW+R), M3: direct seeded rice (DSR) followed by ZTW+R (DSR/ZTW+R). Sub-plots treatments consisted K management practices i.e., K0 : Control, K1 : 40 kg K2O ha-1 Basal, K2 : 40 kg K2O ha-1 two equal splits, K3 : 60 kg K2O ha-1 Basal, K4 : 60 kg K2O ha-1 two equal splits, K5 : 80 kg K2O ha-1 Basal, K6 : 80 kg K2O ha-1 two equal splits, K7 : 60 kg K2O ha-1 Basal +KSB and K8 : 30 kg K2O ha-1 MOP+10 kg K2O ha-1 VC+KSB. Rice variety ‘Rajendra sweta’ was transplanted at spacing of 20 cm × 15 cm using seed rate of 40 kg ha-1 whereas, wheat variety ‘HD2967’ was sown 20 cm apart using a seed rate of 100 kg ha-1. The soil of the experimental plot was well drained, sandy loam in texture, almost neutral in reaction, low in OC and N while medium in P and K. Results revealed that growth parameters, yield attributing characters and grain yield were observed highest in rice under PTR followed by ZT wheat (M2) and in wheat under DSR followed by ZT wheat (M3), under crop establishment methods. In potassium management practices significantly higher number of effective tillers, numbers of grains panicle-1/earhead-1 and grain yield of rice and wheat crop were noticed in 60 kg K2O ha-1 in two equal splits (K4) as compared to recommended dose of K i.e., 40 kg K2O ha-1 and it was statistically at par with K3, K5, K6, K7 and K8. System rice equivalent yield (SREY) (kg ha-1) was significantly influenced by establishment methods, and the highest was observed about 4.4 % more in M2 as compared to M1 while, it was statistically at par with M3. SREY were significantly influenced by K management practices, SREY increased with increase in K level from 40 to 60 kg K2O ha-1. The SREY did not vary significantly between (K4), (K5) and (K6). The SREY obtained with K4 were 11.13 % more as compared to recommended dose (K1, K2), while it was statistically similar with K5, K6 and K7 treatments. Potassium uptake did not vary significantly under crop establishment methods of rice-wheat cropping system, while in potassium management practices 80 kg K2O ha-1 in two equal splits (K6) recorded significantly higher nutrient content and uptake, while it was statistically at par with K3, K4, K5 and K7. Potassium use efficiency (AEk) (%) did not vary significantly under crop establishment methods of rice-wheat cropping system, 30 kg K2O ha-1 through MOP+10 kg K2O ha-1 through VC+KSB (K8) recorded higher AEk in K management practices, while it was statistically at par with K4 and K7 treatments. In economics of rice-wheat cropping system M3 noted maximum net return (Rs. 1,11,177, 1,14,853 ha-1) and B:C ratio (1.59, 1.65), during first and second years, respectively under crop establishment methods, while in potassium management practices K4 recorded maximum net return (Rs. 1,18,737, 1,20,663 ha-1) and B:C ratio (1.63, 1.65), during first and second years, respectively and it was statistically at par with K3, K6 and K7 treatments. The experiment confirmed that crop establishment methods and potassium management with straw retention alleviated soil K depletion and enhanced soil K fertility, and optimum rate of K inputs enhanced their effects. Different potassium management strategies influenced soil available K mainly in the top 15 cm of soil that is suitable for plant uptake and higher crop yield. It was concluded that higher growth and yield of rice-wheat cropping system can be realized by establishing the crops as PTR followed by ZT wheat (M2) and fertilizing the crops with 60 kg K2O ha-1 in two equal splits (K4) was found better among other treatments in respect of crop productivity as well as profitability of rice-wheat cropping system.
