Weed management has become the most important and inevitable aspect of crop management for achieving a higher rice yield. Nowadays, chemical herbicide application has become a popular practice for managing weeds in different rice cultures. However, herbicide application can have qualitative and quantitative impacts on soil microorganisms and soil enzymes, particularly in the case of new herbicide molecules and their indiscriminate use for a longer period. Further, different rice establishment methods also play a significant role in soil microbial population dynamics as well as soil biological properties. Keeping these in view, a field experiment was conducted at the Agronomy Main Research Farm, Orissa University of Agriculture and Technology (OUAT), India, during the kharif season of 2016 and 2017, on the impact of crop establishment methods and weed management practices on soil microbial and enzymatic status. The field experiment was laid out in a split-plot design with three replications with four crop establishment methods in the main plot, viz., M₁, Direct Seeded Rice (DSR); M₂, Wet Seeded Rice (WSR); M₃,Unpuddled Transplanted Rice (NPTR); M₄, Puddled Transplanted Rice (PTR), and six weed management practices in the sub-plot, viz., W₁, Weedy check; W₂, Bensulfuron methyl 0.6% + Pretilachlor 6% (pre-emergence (PE)) 0.660 kg ha⁻¹ + Hand weeding (HW) at 30 days after sowing/transplanting (days after sowing/transplanting (DAS/T)); W₃, Bensulfuron methyl 0.6% + Pretilachlor 6% (PE) 0.495 kg ha⁻¹ + HW at 30 DAS/T; W₄, Bensulfuron methyl 0.6% + Pretilachlor 6% (PE) 0.495 kg ha⁻¹ + Bispyribac-Sodium (post-emergence(POE)) 0.025 kg ha⁻¹ at 15 DAS/T; W₅, Cono weeding (CW) at 15 DAS/T + hand weeding 30 DAS/T, and W₆, Brown manuring/Green manuring. The initial decline in the microbial population was observed due to herbicide application in NPTR and PTR up to 7 DAS/T and then it increased up to 28 DAS/T. There was a reduction in soil microbial and enzymatic status after the application of herbicides Bensulfuron methyl 0.6% + Pretilachlor 6% (PE) and Bispyribac-Sodium (POE) that again followed an upward graph with crop age. Significant variation in enzymatic activity and the microbial count was also observed among treatments involving crop establishment methods. The study revealed that improved microbial population and enzyme activity were noted in unpuddled transplanted rice under organic weed management due to favorable conditions, and chemical weed control initially affected microbial population and activities.

This research illustrates the technical efficiency of the pan-India paddy cultivation status obtained through a stochastic frontier approach. The results suggest that the mean technical efficiency varies from 0.64 in Gujarat to 0.95 in Odisha. Inputs like human labor, mechanical labor, fertilizer, irrigation and insecticide were found to determine the yield in paddy cultivation across India (except for Chhattisgarh). Inefficiency in the paddy production in Punjab, Bihar, West Bengal, Andhra Pradesh, Tamil Nadu, Kerala, Assam, Gujarat and Odisha in 2016–2017 was caused by technical inefficiency due to poor input management, as suggested by the significant σ²U and σ²v values of the stochastic frontier model. In addition, most of the farm groups in the study operated in the high-efficiency group (80–90% technical efficiency). No specific pattern of input use can be visualized through descriptive measures to give any specific policy implication. Thus, machine learning algorithms based on the input parameters were tested on the data in order to predict the farmers’ efficiency class for individual states. The highest mean accuracy of 0.80 for the models of all of the states was achieved in random forest models. Among the various states of India, the best random forest prediction model based on accuracy was fitted to the input data of Bihar (0.91), followed by Uttar Pradesh (0.89), Andhra Pradesh (0.88), Assam (0.88) and West Bengal (0.86). Thus, the study provides a technique for the classification and prediction of a farmer’s efficiency group from the levels of input use in paddy cultivation for each state in the study. The study uses the DES input dataset to classify and predict the efficiency group of the farmer, as other machine learning models in agriculture have used mostly satellite, spectral imaging and soil property data to detect disease, weeds and crops.

A field experiment on the efficacy of some insecticides in combination with neem against rice green leaf hoppers (GLH), Nephotettix virescens Distant, N. nigropictus Stal, and gundhi bug Leptocorisaacuta Thunberg was conducted during kharif 2017 at the Central Research Farm, Department of Entomology, Odisha University of Agriculture and Technology (OUAT), Bhubaneswar. Seven treatments viz., flonicamid 50%WG @ 75g a.i./ha, buprofezin 25%SC @ 200 ml a.i/ha, imidacloprid17.8% SL@35g a.i/ha, flonicamid 50%WG @ 37.5 g a.i./ha + multineem (300ppm) @ 1.25l/ha, buprofezin 25%SC @ 100 ml a.i./ha+ multineem (300ppm) @ 2.5l/ha, imidacloprid 17.8%SL @ 17.5 ml a.i./ha + multineem (300ppm) @ 1.25l/ ha, and multineem (300ppm) @ 2.5l/ha were evaluated. Results revealed that foliar spray of imidacloprid 17.8%SL @ 17.5 ml a.i./ha+ multineem (300 ppm) @ 1.25l/ha at 55 days after spraying (DAS) and 70 DAS were the most effective with 87.77% and 88.91% reduction of GLH and gundhi bug, respectively followed by imidacloprid 17.8%SL@35g a.i/ha with 85.73% and 85.14% reduction, respectively.

Finding a suitable crop establishment strategy that sustains rice production vis-à-vis soil health with minimum loss of yield due to weed menace is the need of the hour. A field experiment was conducted during 2016–17 and 2017–18 on the development of an innovative rice establishment method coupled with the best weed management for rice–green gram system. Establishment methods comprised of direct mechanical seeding of rice (DSR), sprouted rice seedling (WSR), rice transplanting in unpuddled soil (NPTR), and rice transplanting in puddled soil (PTR). There was six weed control measures viz. weedy check [W1), bensulfuron methyl 0.6% + pretilachlor 6% (pre emergence(PE)) at 0.660 kgha-1followed by (fb)manual weeding (HW) at 30 days after sowing or transplanting (DAS/T) [W2), W2 herbicidesat0.495kg ha-1fb HW at 30 (DAS/T) [W3), W2 herbicidesat0.495kgha-1fb0.025 kg ha-1 of bispyribac sodium (post emergence (POE)) at during 15 DAS/T [W4), mechanical weeding during 15 DAS/T using cono weeder (CW) fb hand weeding at 30 DAS/T [W5), and brown manuring/ green manuring [W6). The study revealed that the highest nutrient uptake by rice was found under PTR, thereby resulting in the best rice yield. Weed management W2 resulted in better weed management and yield of the crops. The soil NPK balance was found to be best under the brown/green manured plot, while under different establishment methods, the best N-balance was found in DSR. However, this establishment was found to be poor concerning P and K balance in soil.