Corrigendum: Sensor-based precision nutrient and irrigation management enhances the physiological performance, water productivity, and yield of soybean under system of crop intensification

[This corrects the article DOI: 10.3389/fpls.2023.1282217.].

Sensor-based precision nutrient and irrigation management enhances the physiological performance, water productivity, and yield of soybean under system of crop intensification

Sensor-based decision tools provide a quick assessment of nutritional and physiological health status of crop, thereby enhancing the crop productivity. Therefore, a 2-year field study was undertaken with precision nutrient and irrigation management under system of crop intensification (SCI) to understand the applicability of sensor-based decision tools in improving the physiological performance, water productivity, and seed yield of soybean crop. The experiment consisted of three irrigation regimes [I1: standard flood irrigation at 50% depletion of available soil moisture (DASM) (FI), I2: sprinkler irrigation at 80% ETC (crop evapo-transpiration) (Spr 80% ETC), and I3: sprinkler irrigation at 60% ETC (Spr 60% ETC)] assigned in main plots, with five precision nutrient management (PNM) practices{PNM1-[SCI protocol], PNM2-[RDF, recommended dose of fertilizer: basal dose incorporated (50% N, full dose of P and K)], PNM3-[RDF: basal dose point placement (BDP) (50% N, full dose of P and K)], PNM4-[75% RDF: BDP (50% N, full dose of P and K)] and PNM5-[50% RDF: BDP (50% N, full P and K)]} assigned in sub-plots using a split-plot design with three replications. The remaining 50% N was top-dressed through SPAD assistance for all the PNM practices. Results showed that the adoption of Spr 80% ETC resulted in an increment of 25.6%, 17.6%, 35.4%, and 17.5% in net-photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), and intercellular CO2 concentration (Ci), respectively, over FI. Among PNM plots, adoption of PNM3 resulted in a significant (p=0.05) improvement in photosynthetic characters like Pn (15.69 µ mol CO2 m-2 s-1), Tr (7.03 m mol H2O m-2 s-1), Gs (0.175 µmol CO2 mol-1 year-1), and Ci (271.7 mol H2O m2 s-1). Enhancement in SPAD (27% and 30%) and normalized difference vegetation index (NDVI) (42% and 52%) values were observed with nitrogen (N) top dressing through SPAD-guided nutrient management, helped enhance crop growth indices, coupled with better dry matter partitioning and interception of sunlight. Canopy temperature depression (CTD) in soybean reduced by 3.09-4.66°C due to adoption of sprinkler irrigation. Likewise, Spr 60% ETc recorded highest irrigation water productivity (1.08 kg ha-1 m-3). However, economic water productivity (27.5 INR ha-1 m-3) and water-use efficiency (7.6 kg ha-1 mm-1 day-1) of soybean got enhanced under Spr 80% ETc over conventional cultivation. Multiple correlation and PCA showed a positive correlation between physiological, growth, and yield parameters of soybean. Concurrently, the adoption of Spr 80% ETC with PNM3 recorded significantly higher grain yield (2.63 t ha-1) and biological yield (8.37 t ha-1) over other combinations. Thus, the performance of SCI protocols under sprinkler irrigation was found to be superior over conventional practices. Hence, integrating SCI with sensor-based precision nutrient and irrigation management could be a viable option for enhancing the crop productivity and enhance the resource-use efficiency in soybean under similar agro-ecological regions.

Integrated management enhances crop physiology and final yield in maize intercropped with blackgram in semiarid South Asia

Photosynthesis, crop health and dry matter partitioning are among the most important factors influencing crop productivity and quality. Identifying variation in these parameters may help discover the plausible causes for crop productivity differences under various management practices and cropping systems. Thus, a 2-year (2019-2020) study was undertaken to investigate how far the integrated crop management (ICM) modules and cropping systems affect maize physiology, photosynthetic characteristics, crop vigour and productivity in a holistic manner. The treatments included nine main-plot ICM treatments [ICM₁ to ICM₄ - conventional tillage (CT)-based; ICM₅ to ICM₈ - conservation agriculture (CA)-based; ICM₉ - organic agriculture (OA)-based] and two cropping systems, viz., maize-wheat and maize + blackgram-wheat in subplots. The CA-based ICM module, ICM₇ resulted in significant (p < 0.05) improvements in the physiological parameters, viz., photosynthetic rate (42.56 μ mol CO₂ m^-2 sec^-1), transpiration rate (9.88 m mol H₂O m^-2 sec^-1) and net assimilation rate (NAR) (2.81 mg cm^-2 day^-1), crop vigour [NDVI (0.78), chlorophyll content (53.0)], dry matter partitioning toward grain and finally increased maize crop productivity (6.66 t ha^-1) by 13.4-14.2 and 27.3-28.0% over CT- and OA-based modules. For maize equivalent grain yield (MEGY), the ICM modules followed the trend as ICM₇ > ICM₈ > ICM₅ > ICM₆ > ICM₃ > ICM₄ > ICM₁ > ICM₂ > ICM₉. Multivariate and PCA analyses also revealed a positive correlation between physiological parameters, barring NAR and both grain and stover yields. Our study proposes an explanation for improved productivity of blackgram-intercropped maize under CA-based ICM management through significant improvements in physiological and photosynthetic characteristics and crop vigour. Overall, the CA-based ICM module ICM₇ coupled with the maize + blackgram intercropping system could be suggested for wider adoption to enhance the maize production in semiarid regions of India and similar agroecologies across the globe.

Double zero-tillage and foliar-P nutrition coupled with bio-inoculants enhance physiological photosynthetic characteristics and resilience to nutritional and environmental stresses in maize-wheat rotation

Conventionally tilled maize-wheat cropping system (MWCS) is an emerging cereal production system in semi-arid region of south-Asia. This system involves excessive tillage operations that result in numerous resource- and production-vulnerabilities besides impeding environmental-stresses. Likewise, phosphorus is a vital nutrient that limits crop growth and development. It's a matter of great concern when ∼80% of Indian soils are low to medium in available-P due to its sparing solubility, resulting in crop stress and low yields. Hence, crop productivity, photosynthetic parameters and resilience to nutritional and environmental stresses were assessed in a MWCS using four crop-establishment and tillage management (CETM) practices [FBCT-FBCT (Flat bed-conventional tillage both in maize and wheat); RBCT-RBZT (Raised bed-CT in maize and raised bed-zero tillage in wheat); FBZT-FBZT (FBZT both in maize and wheat); PRBZT-PRBZT (Permanent raised bed-ZT both in maize and wheat)], and five P-fertilization practices [P₁₀₀ (100% soil applied-P); P₅₀+2FSP (50% soil applied-P + 2 foliar-sprays of P through 2% DAP both in maize and wheat); P₅₀+PSB+AM-fungi; P₅₀+PSB+AMF+2FSP; and P₀ (100% NK with no-P)] in split-plot design replicated-thrice. The results indicated that double zero-tilled PRBZT-PRBZT system significantly enhanced the grain yield (6.1; 5.4 t ha^-1), net photosynthetic rate (Pn) (41.68; 23.33 μ mol CO₂ m^-2 s^-1), stomatal conductance (SC) (0.44; 0.26 mol H₂O m^-2 s^-1), relative water content (RWC) (83.3; 77.8%), and radiation-use efficiency (RUE) (2.9; 2.36 g MJ^-1) by 12.8-15.8 and 8.5-44.4% in maize and wheat crops, respectively over conventional tilled FBCT-FBCT. P₅₀+PSB+AMF+2FSP conjugating soil applied-P, microbial-inoculants and foliar-P, had significantly higher Pn, SC, RUE and RWC over P₁₀₀ besides saving ∼34.7% fertilizer-P under MWCS. P₅₀+PSB+AMF+2FSP practice also had higher NDVI, PAR, transpiration efficiency and PHI over P₁₀₀. Whereas lower stomatal limitation index (Ls) was observed under PRBZT-PRBZT system as compared to the conventional FBCT-FBCT system indicating that P is the limiting factor but not stomata. Hence, optimum P supply through foliar P-fertilization along with other sources resulted in higher grain yield by 21.4% over control. Overall, double zero-tilled PRBZT-PRBZT with crop residue retention at 6 t/ha per year, as well as P₅₀+PSB+AMF+2FSP in MWCS, may prove beneficial in enhancing the crop productivity and, thereby, bolstering food security in semi-arid south-Asia region.

Double zero tillage and foliar phosphorus fertilization coupled with microbial inoculants enhance maize productivity and quality in a maize-wheat rotation

Maize is an important industrial crop where yield and quality enhancement both assume greater importance. Clean production technologies like conservation agriculture and integrated nutrient management hold the key to enhance productivity and quality besides improving soil health and environment. Hence, maize productivity and quality were assessed under a maize–wheat cropping system (MWCS) using four crop-establishment and tillage management practices [FBCT–FBCT (Flat bed–conventional tillage both in maize and wheat); RBCT–RBZT (Raised bed–CT in maize and raised bed–zero tillage in wheat); FBZT–FBZT (FBZT both in maize and wheat); PRBZT–PRBZT (Permanent raised bed–ZT both in maize and wheat], and five P-fertilization practices [P₁₀₀ (100% soil applied-P); P₅₀ + 2FSP (50% soil applied-P + 2 foliar-sprays of P through 2% DAP both in maize and wheat); P₅₀ + PSB + AM-fungi; P₅₀ + PSB + AMF + 2FSP; and P₀ (100% NK with no-P)] in split-plot design replicated-thrice. Double zero-tilled PRBZT–PRBZT system significantly enhanced the maize grain, starch, protein and oil yield by 13.1–19% over conventional FBCT–FBCT. P₅₀ + PSB + AMF + 2FSP, integrating soil applied-P, microbial-inoculants and foliar-P, had significantly higher grain, starch, protein and oil yield by 12.5–17.2% over P₁₀₀ besides saving 34.7% fertilizer-P both in maize and on cropping-system basis. P₅₀ + PSB + AMF + 2FSP again had significantly higher starch, lysine and tryptophan content by 4.6–10.4% over P₁₀₀ due to sustained and synchronized P-bioavailability. Higher amylose content (24.1%) was observed in grains under P₅₀ + PSB + AMF + 2FSP, a beneficial trait due to its lower glycemic-index highly required for diabetic patients, where current COVID-19 pandemic further necessitated the use of such dietary ingredients. Double zero-tilled PRBZT–PRBZT reported greater MUFA (oleic acid, 37.1%), MUFA: PUFA ratio and P/S index with 6.9% higher P/S index in corn-oil (an oil quality parameter highly required for heart-health) over RBCT-RBCT. MUFA, MUFA: PUFA ratio and P/S index were also higher under P₅₀ + PSB + AMF + 2FSP; avowing the obvious role of foliar-P and microbial-inoculants in influencing maize fatty acid composition. Overall, double zero-tilled PRBZT–PRBZT with crop residue retention at 6 t/ha per year along with P₅₀ + PSB + AMF + 2FSP while saving 34.7% fertilizer-P in MWCS, may prove beneficial in enhancing maize productivity and quality so as to reinforce the food and nutritional security besides boosting food, corn-oil and starch industry in south-Asia and collateral arid agro-ecologies across the globe.

Clinical practice guidelines for the noninvasive management of low back pain: A systematic review by the Ontario Protocol for Traffic Injury Management (OPTIMa) Collaboration

We conducted a systematic review of guidelines on the management of low back pain (LBP) to assess their methodological quality and guide care. We synthesized guidelines on the management of LBP published from 2005 to 2014 following best evidence synthesis principles. We searched MEDLINE, EMBASE, CINAHL, PsycINFO, Cochrane, DARE, National Health Services Economic Evaluation Database, Health Technology Assessment Database, Index to Chiropractic Literature and grey literature. Independent reviewers critically appraised eligible guidelines using AGREE II criteria. We screened 2504 citations; 13 guidelines were eligible for critical appraisal, and 10 had a low risk of bias. According to high-quality guidelines: (1) all patients with acute or chronic LBP should receive education, reassurance and instruction on self-management options; (2) patients with acute LBP should be encouraged to return to activity and may benefit from paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs), or spinal manipulation; (3) the management of chronic LBP may include exercise, paracetamol or NSAIDs, manual therapy, acupuncture, and multimodal rehabilitation (combined physical and psychological treatment); and (4) patients with lumbar disc herniation with radiculopathy may benefit from spinal manipulation. Ten guidelines were of high methodological quality, but updating and some methodological improvements are needed. Overall, most guidelines target nonspecific LBP and recommend education, staying active/exercise, manual therapy, and paracetamol or NSAIDs as first-line treatments. The recommendation to use paracetamol for acute LBP is challenged by recent evidence and needs to be revisited.

SIGNIFICANCE

Most high-quality guidelines recommend education, staying active/exercise, manual therapy and paracetamol/NSAIDs as first-line treatments for LBP. Recommendation of paracetamol for acute LBP is challenged by recent evidence and needs updating.