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The sustainability of agricultural production systems is significantly threatened due to climate change and land degradation. Agricultural practices like conventional tillage with imbalanced fertilizers, and indiscriminate irrigation have serious environmental implications like higher greenhouse gas (GHG) emissions. Therefore, we assessed the three-year productivity, effectiveness of energy, and carbon (C) footprint of soybean–wheat system under different tillage techniques [zero-till flat beds (ZTFB), conventional till-raised beds (CTRB), and conventional till- flat beds (CTFB)], irrigation regimes [irrigation at 25%, 50%, and 75% depletion of available soil moisture (DASM)] and fertilizer rates [50% and 100% recommended rates of fertilizers (RRF). The study was conducted for three years in a fixed-field plots using split-split plot design with three replications. The results show that conventional till-raised bed (CTRB) recorded higher system crop productivity (9.5–15.2%), energy-efficiency (17.3), C-output (6424), C-efficiency (11.7), C-sustainability index (9.73), net-returns (1035 US$ ha−1) and the least C-footprints (0.19) over conventional till-flat beds (CTFB) and zero till-flat beds (ZTFB). Whereas, residue mulched ZTFB plots exhibited ∼24.2% higher system water productivity and consumed less energy (∼77.0%) over others. Irrigation applied at 25% depletion of available soil moisture (DASM 25%) led to higher system productivity (5.96 Mg ha−1), energy output (232.6 GJ ha−1), energy-efficiency (13.4) and C-output (6657.4 kg CE ha−1) compared to DASM 75% and DASM 50%. Interestingly, C-footprints increased with ZTFB while least C-footprints were found under CTRB and CTFB. Consequently, the adaptation of CTRB with optimal irrigation and fertilizers will be a viable alternative for achieving improved system production, energy efficiency with a lower C-footprint under semi-arid regions. • Assessed soybean-wheat carbon footprint (CFs) for tillage, irrigation and fertilizers. • Raised beds (FIRB) enhanced system productivity, energy-efficiency, and C-index. • CFs are highest in zero-till+residue (ZTFB), while least under raised-beds. • ZTFB resulted in ∼5.6%− 31.1% increase in soybean and wheat yields over control. • Raised-beds+DASM 25% +fertilizer 100% improved energy efficiency, while reducing CFs. [ABSTRACT FROM AUTHOR]

Maize cultivation for green cobs during the spring season is a remunerative proposition for the farmers in the north Indian plains. However, high evapo-transpiration demand of spring maize exerts considerable pressure on already depleting water resources. Thus, a two-year field experiment was conducted at GBPUA & T, Pantnagar, Uttarakhand, India to determine the effect of rice residue mulch, earthing-up, alternate furrow irrigation and crop establishment methods on productivity, profitability and irrigation water use efficiency (IWUE) of spring maize. Results revealed that application of rice straw mulch (6 t/ha) enhanced plant height, number of green leaves, dry matter accumulation, leaf area index and yield attributes. Reproductive stage set in advance in mulch treated plots compared to plots under other treatments. Green cob yield from mulched plot was the highest that was 37 % higher over the flat planting alone. Broad bed planting and flat planting followed by earthing-up treatments produced the second and third highest cob yield, respectively. Planting on broad bed registered the highest IWUE (352.5 kg/ha-cm). Mulch treatment also earned higher net returns and B : C ratio than remaining treatments. [ABSTRACT FROM AUTHOR]

The impact of arbuscular mycorrhizal fungi (AMF), inorganic phosphorus (P), and irrigation regimes was studied in an okra (Abelmoschus esculentus)–pea (Pisum sativum) cropping system in an acidic Alfisol. Experimentation was carried out at Palampur, India, in a randomized bock design (RBD), replicated three times with fourteen treatments comprising AM fungi (Glomus mosseae), inorganic phosphorus (50, 75, and 100% soil-test-based recommended P dose), irrigation regimes (at 40 and 80% available water capacity), generalized recommended NPK and irrigations (GRD), and farmers’ practice. Effects of AM fungi on plant height, leaf area index (LAI), and dry-matter accumulation (DMA) were nominal at early crop growth stage, i.e., 50 DAS (days after sowing). However, at 100 DAS, AMF imbedded treatments led to higher plant height (4%), LAI (3%), and DMA (6%) in okra, whereas in pea the magnitude of increase in these parameters following AMF inoculation was 6, 5, and 8%, respectively, over non-AMF counterparts. AMF + 75% soil-test-based P dose at either of these irrigation regimes gave statistically similar yields in both okra and pea as that obtained under 100% soil-test-based P dose at either of two irrigation regimes, thus indicating an economy of about 25% in soil-test-based P dose. Regarding nutrient harvest index in okra and pea, statistically similar values were registered with most nutrients under both AMF inoculated and non-AMF counterparts. In the case of okra, P harvest index was registered less by 3% with AMF inoculation; however, its magnitude increased by 3% in pea following AMF inoculation compared to non-AMF counterparts at similar levels of P and irrigation. At completion of two cycles of okra-pea system, AMF imbedded treatments did not alter available soil nutrient status significantly in comparison to non-AMF counterparts. Overall, current study suggests that practice of AMF inoculation has great potential in enhancing growth parameters for better productivity, fertilizer-P economy, and nutrient harvest efficiency in okra-pea production system in Himalayan acidic Alfisol. [ABSTRACT FROM PUBLISHER]

Field experiments were conducted on a Typic Hapludoll (Mollisols) soil in the Indo-Gangetic Plains of India during the 2008 and 2009 rainy seasons to (1) find out the effect of irrigation schedules and plant spacing on physiological parameters, yield and water productivity of two rice cultivars under System of Rice Intensification (SRI), and (2) compare the performance of SRI with conventional transplanting (CT). Treatments under SRI included 12 combinations of three irrigation schedules, viz. irrigation at 1, 3 and 5 day(s) after disappearance of ponded water (DADPW), two spacing intervals (20 × 20 cm and 25 × 25 cm) and two cultivars (‘Pant Dhan 4’ and ‘Hybrid 6444’). The two control treatments were the CT of each cultivar. The experiment was set in a factorial randomized complete block design replicated thrice. The net photosynthetic rate (NPR) of the topmost fully expanded leaf at tillering and that of flag-leaf at flowering stage was affected significantly by irrigation schedules. Irrigating rice crop at 1 or 3 DADPW, being at par with each other, recorded significantly higher NPR than 5 DADPW. The increase in NPR at 1 and 3 DADPW was 17.1% and 8.4% at tillering and 13.6% and 6.1% at flowering stage, respectively, compared with that at 5 DADPW (tillering: 12.78 μmol CO2 m−2 S−1, flowering: 16.01 μmol CO2 m‑2 S−1). At closer spacing (20 × 20 cm) the cultivars did not differ significantly for NPR; however, at wider spacing (25 × 25 cm), ‘Hybrid 6444’ showed significantly higher NPR than ‘Pant Dhan 4’. Between two methods, SRI recoded higher NPR. Dry matter accumulation (DMA) in leaves and grains declined with delay in irrigation from 1 to 5 DADPW. Wider spacing significantly enhanced DMA in stems and grains. ‘Hybrid 6444’ showed higher DMA in all plant parts than ‘Pant Dhan 4’. Grain yield was not affected significantly by irrigation schedules in 2008, while in 2009, irrigation at 1 and 3 DADPW resulted in 12.8% and 8.0% higher grain yield, respectively, than 5 DADPW (5.84 t ha−1). Wider spacing was superior to closer spacing. SRI improved grain yield by 16.9% and water productivity by 18.5% over CT. [ABSTRACT FROM AUTHOR]