EddyPro checks for signal quality and gas analyzer signal strength (which depends on the cleanliness of sensor optical windows and/or presence or absence of rain drops/fog in the measuring volume). A missing samples allowance of 10% was set for the raw data in the flux averaging intervals and linear interpolation of the data is done by Eddy pro within this limit. The effect of wind blowing normal to the sonic path on the speed of sound (sonic temperature) is corrected for in the CSAT3 firmware(CSAT3 3-D Sonic Anemometer Instruction Manual). Other corrections are as follows.

Agriculture in a water-limited environment is critically important for today and for the future. This research evaluates the impact of deficit irrigation in different planting methods on the physio-morphological traits, grain yield and WUE of maize (Zea mays L.). The experiment was carried out in 2015 and 2016, consisting of three planting methods (i.e., BBF, SNF, and DWF) and four irrigation levels (i.e., I10D: irrigation once in ten days, I40: irrigation at 40% DASM, I50: irrigation at 50% DASM, and I60: irrigation at 60% DASM). The results reveal that varying degrees of water stress due to planting methods and irrigation levels greatly influenced the maize physio-morphological traits and yield attributes. The combined effect of DWF + I50 benefited the maize in terms of higher leaf area, RWC, SPAD values, CGR, and LAD, followed by the SNF method at 60 DAS. As a result, DWF + I50 and SNF + I50 had higher 100 grain weight (30.5 to 31.8 g), cob weight (181.4 to 189.6 g cob−1) and grain yield (35.3% to 36.4%) compared to other treatments. However, the reduction in the number of irrigations (24.0%) under SNF + I50 resulted in a 34% water saving. Thus, under a water-limited situation in semi-arid tropics, the practice of the SNF method + I50 could be an alternative way to explore the physio-morphological benefits in maize.

No abstract

Assessing the impact of planting methods and irrigation levels is needed to determine the effects on maize root morphological traits, grain yield, and water productivity in semi-arid regions. A study was initiated on maize (Zea mays L.) from 2015 to 2016, including three planting methods [i.e. broad bed and furrow (BBF), shallow and narrow furrow (SNF) and deep and wider furrow (DWF)] and four irrigation levels [i.e. irrigation once in ten days (I10D), irrigation at 40% depletion of available soil moisture (DASM, I40), irrigation at 50% DASM (I50) and irrigation at 60% DASM (I60)] arranged in a split-plot design with three replications. Results reveal that the DWF method has increased root length, root volume, root surface area and root dry weight compared to SNF and BBF (p < 0.05). DWF and SNF resulted in higher grain yield than BBF, although the DWF grain yield was non-significant with SNF but resulted in 22.40% higher irrigation application. Irrigation at I50 had a significant effect on root length, root surface area, and grain yield, regardless of planting methods. Therefore, where irrigation has been a costly and limited farm input, the practice of SNF and deficit irrigation (I50) could be a viable option for greater water saving and higher grain yields of maize.

The main aim of land configurations is in situ conservation of soil moisture by increasing the opportunity time for augmented water use efficiency and drain out excess water. The field study was conducted for two years under rainfed conditions of Dharwad on residual soil moisture and fertility. Cowpea produced higher grain yield (13.4 q ha -1 ), haulm yield (25.6 q ha -1 ) and harvest index (34.4 %) with Broad Bed and Furrow (BBF) method of planting. Similarly, BBF method resulted in higher soil moisture content (32.09 % at 40 DAS) and rain water use efficiency (RWUE) of 5.96 kg ha-mm -1 . The RWUE had a significant and highly positive correlation with soil moisture at 40 and 55 DAS (with r value of r=0.94** and r=0.96**, respectively). BBF method of planting also registered higher gross return (Rs.42725 ha -1 ), net return (¹ 27515 ha -1 ) and benefit-cost ratio (2.82). Cowpea can be grown successfully after summer maize on existing BBF configuration for higher yield and rain water use efficiency.

The aim of this study was to explore the effect of sowing methods and deficit irrigation on weed dynamics, yield and water-use efficiency (WUE) of the maize–cowpea system during the summer and monsoon seasons, respectively. The field experiment was carried out for two years (2015 and 2016) using a split design with three replicates under irrigated (maize) and rainfed (cowpea) conditions on vertisols of a semi-arid region. Treatments included three sowing methods [i.e., broad bed and furrow (BBF), corrugated furrow (CF) and ridges and furrow (RF)] and four irrigation levels [i.e., irrigation once in 10 days (I10D), irrigation at 40% (I40), at 50% (I50) and at 60% (I60) depletion]. The results indicated that, regardless of weed flora (monocots, dicots and sedges), the RF method produced higher weed density (2.09–2.98 No. m−2) compared to CF (2.00–2.80 No. m−2) and BBF (1.85–2.64 No. m−2) in maize at 30 and 60 days after sowing (DAS). The RF method with irrigation at I40 and I50 recorded significantly higher weed density, followed by the CF and BBF method. A similar trend was also observed with dry weight of weeds (monocot; 24.19%, dicot; 25.52%, and sedges; 29.80%) in maize at 30 and 60 DAS. Higher weed density and dry weight of weeds in the RF method with I40 was due to higher soil moisture availability and higher nutrient uptake due to larger lateral wetting of the soil and greater water use (29.27%). However, the BBF method favoured the growth of weeds (9.33–16.60%) in cowpea at 55 DAS and coped under rain-fed situation over CF and RF. The CF with moderate depletion (I50) method produced significantly higher maize equivalent yield (MEY) of cowpea (10,000 kg ha−1) with considerable reduction in the total water usage (19.33%). Therefore, under a water scarcity situation, growers can practice CF and I50 for higher yield and WUE of maize–cowpea sequence cropping.

A field experiment was conducted to study the effect of tillage, mulching and weed management practices on growth, yield and uptake of nutrients by chickpea during rabi 2010 and 2011 at MARS, UAS Dharwad, Karnataka. Conventional tillage increased various growth, yield parameters and chickpea yield and also nutrient uptake and nitrogen use efficiency over minimum and zero tillage practices. Significantly higher gross return, net return and B:C ratio were recorded in conventional tillage as compared to minimum and zero tillage practices. Mulching practice showed higher growth, yield and yield parameters of chickpea and also nutrient uptake and economics over minimum and zero tillage practices. Significantly higher growth, chickpea yield and yield parameters, nutrient uptake, gross return, net return and B:C ratio were recorded in application of pendimethalin as compared to other weed management practices.

A field experiment was conducted during summer 2018 and 2019 to study the performance of maize (Zea mays L.) genotypes under drip and furrow irrigation regimes at the Main Agriculture Research Station, University of Agricultural Sciences, Dharwad, Karnataka. The experiment was laid out in strip plot design with 3 replications. Treatments included 4 irrigation levels (drip irrigation at 0.6 ETc, 0.8 ETc and 1.0 ETc and furrow irrigation at 0.8 IW/CPE ratio) and 4 maize genotypes. The data indicated that, furrow irrigation at 0.8 IW/CPE ratio and drip irrigation at 1.0 ETc recorded significantly higher and on par growth and yield parameters, grain yield (75.8 q/ha and 71.4 q/ha, respectively) and economic returns. Drip irrigation at 1.0 ETc consumed 28.6% less water but recorded significantly higher water productivity over furrow irrigation. Among the genotypes, NK-6240 found superior over rest of the genotypes. The combination of furrow irrigation with NK-6240 recorded significantly higher growth and yield attributes as well as grain yield and economics over rest of the combinations. However, this treatment remained statistically non-significant with drip irrigation at 1.0 ETc with NK-6240 and furrow irrigation with CP-818.