Cumulative Pan Evaporation Research Articles

Effects of different irrigation methods and mulching on yield, growth and water use efficiency of strawberry

ABSTRACT A greenhouse experiment was conducted from 2015–2016 to 2017–2018 on an Aeric Haplaquept to evaluate the effect of irrigation (surface irrigation at furrows at irrigation water: cumulative pan evaporation = 1, drip irrigation to meet 100%, 80% and 60% of actual crop evapotranspiration demand), and mulch (nonwoven jute agro textile, biodegradable plastic film, rice straw and no mulch) regimes on strawberry. Average soil water storage in root zone (86 mm) and fraction of potential plant available water (61%) was highest in jute agrotextile mulched and drip irrigated at 80% actual evapotranspiration. This combination of mulch and irrigation regime increased belowground (root length density, 7.15 × 103 mm−3) and above ground (leaf area index, 9.4) crop growth and emerged as the best option with three- and four-times higher yield (31.1 Mg ha −1) and water use efficiency (23.1 kg m−3), respectively than surface irrigated unmulched strawberry. Results suggest that these findings be incorporated into packages and practices of strawberry cultivation in the moist tropical sub-humid region of Bengal basin and other similar agroecological regions of South Asia.

Microbial population and yield of rice–wheat system under variable irrigation and nutrient management

A field experiment was conducted during rainy (kharif) season of 2018–19 and winter (rabi) season of 2019–20 at the Water Management Research Farm of CSK Himachal Pradesh Agricultural University, Palampur, Kangra, Himachal Pradesh to study the effect of moisture and nutrient management practices on different soil microbial entities and crop yields in rice (Oryza sativa L.)–wheat (Triticum aestivum L.) system. Experiment was laid out in a split-plot design with 3 replications. Treatments comprised of 3 irrigation levels, viz. Recommended critical stages regimes; Irrigation at 0.8 CPE (cumulative pan evaporation) (rice) and 0.6 CPE (wheat); Irrigation at 1.0 CPE (rice) and 1.0 CPE (wheat) assigned to main-plots and 4 nutrient management practices, viz. Inorganic; Organic; Natural farming; and Integrated management allotted to sub-plots. Irrigation at critical stages resulted in significantly higher rice yield, bacterial, azotobacter, phosphate solubilizing bacteria (PSB), actinomycetes population. However, fungi population increased under higher moisture regimes. In case of wheat crop, irrigation at 1.0 CPE resulted in a significantly higher yield (7.5% higher over irrigation at critical stages) in both the years of study. Organic and integrated nutrient management practices being statistically at par with each other recorded significantly higher microbial population. A significantly higher fungi population was, however, recorded with natural farming. The highest crop yields were obtained with integrated nutrient management (3.4 t/ha rice and 3.6 t/ha wheat in second year). The best combination for rice was irrigation at critical stages along with integrated nutrient management. Whereas, for wheat irrigation at 1.0 CPE with same nutrient management proved to be the best. Hence it is recommended to follow integrated nutrient management and irrigation at critical stages in rice and at 1.0 CPE in wheat for higher productivity as well as for improved biological properties of soil.

Intercrop and drip irrigation effects on growth, yield, water-use efficiency and economics of elephant foot yam (Amorphophallus paeoniifolius)

A field experiment was conducted during 2012–13 and 2013–14 at Bhubaneswar, Odisha to study the effects of intercrop and drip irrigation on growth, corm yield, water-use efficiency as well as economics of production of elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]. The experiment was laid out in split plot design with 5 replications, keeping elephant foot yam + green gram and elephant foot yam sole crop in the main plots and surface irrigation, drip irrigation at 100% cumulative pan evaporation (CPE), drip irrigation at 80% CPE and drip irrigation at 60% CPE in the sub-plots. The results revealed that, drip irrigation at 60–80% CPE resulted in higher green gram seed yield (630 kg/ha). Elephant foot yam + green gram intercropping system recorded better growth, yield attributes and yield than sole elephant foot yam. Drip irrigation at 100% and 80% CPE realized better growth, yield attributes and yield compared to other treatments. Surface irrigation resulted in higher consumptive use of water (204 cm) than drip irrigation (50, 41 and 30 cm at 100, 80 and 60 CPE respectively). The highest water-use efficiency was noticed in elephant foot yam + green gram intercropping with drip irrigation at 60% CPE (1080 kg/ha-cm). The highest net returns was recorded with elephant foot yam + green gram intercropping with drip irrigation at 100% CPE (309 × 103 /ha), which was statistically at par with elephant foot yam + green gram intercropping with drip irrigation at 80% CPE (307 × 103 /ha). Thus, elephant foot yam and green gram can be grown as an intercrop profitably with application of drip irrigation at 80% CPE to harvest greater yield and realize more returns.

Effect of nutrition management and irrigation methods and schedule on productivity, economics and water-use efficiency in soybean (Glycine max) chickpea (Cicer arietinum) cropping sequence in alluvial soil

A field experiment was conducted during 2011–12 and 2012–13 at Morena, Madhya Pradesh, to study the ef fect of nutrition management, and methods and scheduling of irrigation on soybean [Glycine max (L.) Merr.] chickpea (Cicer arietinum L.) cropping sequence. An irrigation at 0.6 irrigation water:cumulative pan evaporation (IW:CPE) ratio resulted in significantly higher growth, yield attributes, seed yield, economic benefits and water pro ductivity of soybean compared with 0.4 and 0.8 IW:CPE. Similarly, an irrigation at 0.4 IW:CPE ratio significantly in fluenced the yield-attributing characters, seed and straw yields, economic benefits and water productivity of chickpea compared with 0.6 and 0.8 IW:CPE ratios, whereas height and number of branches increased with in creasing IW:CPE ratio. Sprinkler irrigation resulted in significantly higher growth and yield attributes, seed and straw yields, economic benefits and water productivity of both the crops. The irrigation at 0.6 IW:CPE ratio showed 51.3% and 39.0% higher seed of soybean over 0.4 and 0.8 IW:CPE ratio, whereas 0.4 IW:CPE of irrigation yielded 14.5% and 32.5% higher seed of chickpea compared with 0.6 and 0.8 IW:CPE. Mean response of sprinkler irriga tion was recorded 8.3% in soybean and 11.7% in chickpea higher seed yield over check basin irrigation. Likewise, increases in growth and yield attributes, seed yield, water productivity and protein production of soybean and chickpea were noticed with application of 75% recommended dose of fertilizer (RDF) + 2.5 t FYM/ha compared with other nutrition treatments. Addition of 75% RDF + 2.5 t FYM/ha also achieved higher system productivity, net profit and production and economic efficacy. After harvesting of the second crop of chickpea, maximum availability of N, P, K and S was recorded under 0.4 IW:CPE ratio, sprinkler irrigation and application of 75% RDF + 2.5 t FYM/ha compared to other treatments.

Effect of variable irrigation supply based diversification of Bt cotton (Gossypium hirsutum)–wheat (Triticum aestivum) system on productivity, profitability, soil fertility and water expense efficiency

A field experiment was conducted during 2011–12 and 2012–13 at Morena, Madhya Pradesh, to study the ef fect of nutrition management, and methods and scheduling of irrigation on soybean [Glycine max (L.) Merr.] chickpea (Cicer arietinum L.) cropping sequence. An irrigation at 0.6 irrigation water:cumulative pan evaporation (IW:CPE) ratio resulted in significantly higher growth, yield attributes, seed yield, economic benefits and water pro ductivity of soybean compared with 0.4 and 0.8 IW:CPE. Similarly, an irrigation at 0.4 IW:CPE ratio significantly in fluenced the yield-attributing characters, seed and straw yields, economic benefits and water productivity of chickpea compared with 0.6 and 0.8 IW:CPE ratios, whereas height and number of branches increased with in creasing IW:CPE ratio. Sprinkler irrigation resulted in significantly higher growth and yield attributes, seed and straw yields, economic benefits and water productivity of both the crops. The irrigation at 0.6 IW:CPE ratio showed 51.3% and 39.0% higher seed of soybean over 0.4 and 0.8 IW:CPE ratio, whereas 0.4 IW:CPE of irrigation yielded 14.5% and 32.5% higher seed of chickpea compared with 0.6 and 0.8 IW:CPE. Mean response of sprinkler irriga tion was recorded 8.3% in soybean and 11.7% in chickpea higher seed yield over check basin irrigation. Likewise, increases in growth and yield attributes, seed yield, water productivity and protein production of soybean and chickpea were noticed with application of 75% recommended dose of fertilizer (RDF) + 2.5 t FYM/ha compared with other nutrition treatments. Addition of 75% RDF + 2.5 t FYM/ha also achieved higher system productivity, net profit and production and economic efficacy. After harvesting of the second crop of chickpea, maximum availability of N, P, K and S was recorded under 0.4 IW:CPE ratio, sprinkler irrigation and application of 75% RDF + 2.5 t FYM/ha compared to other treatments.

Response of late-sown wheat (Triticum aestivum) to limited irrigation, seed rate and depth of sowing

A field experiment was conducted during the winter (rabi) season of 2014–15 and 2015–16 at New Delhi, to study the effect of limited irrigation, seed rate and depth of sowing on growth, yield, water-use parameters and economics of late-sown wheat (Triticum aestivum L.). The experiment comprised 3 factors, viz. 3 irrigation levels [(I1 , irrigation at crown-root initation (CRI) stage; I2 , irrigation at CRI stage + 0.2 irrigation water: cumulative pan evaporation (IW : CPE) ratio; and I3, irrigation at CRI stage + 0.4 IW : CPE ratio), 3 seed rates (S1, 75; S2, 100 and S2, 125 kg/ha) and 2 depths of sowings (D1, 5 cm and D2 , 10 cm). The field experiment comprising 18 treatment combinations, replicated thrice, was laid out in strip-plot design. Interactions between irrigation levels and seed rates, and irrigation levels and depths of sowing for grain yield were significant during 2014–15. Irrigation levels, seed rates and depths of sowing also significantly affected plant height, yield attributes, grain yield, straw yield and harvest index. Irrigation at CRI stage + 0.4 IW : CPE ratio resulted in significantly the highest plant height (86.3 cm), effective tillers/m2 (407.82), spike length (14.40 cm), spikelets/spike (17.43), grains/spike (44.20), grain weight/spike (2.05 g), 1,000-grain weight (48.95 g), grain yield (4.22 and 3.75 t/ha during 2014–15 and 2015–16) and harvest index (0.497 and 0.477 during respective season). Seed rate of 125 kg/ha resulted in significantly the highest plant height (82.7 cm), effective tillers/m2 (416.66), spike length (14.62 cm), spikelets/spike (17.53), grains/ spike (40.20), grain weight/spike (2.06 g), 1,000-grain weight (47.80 g), grain yield (3.63 t/ha during 2015–16) and harvest index (0.496 and 0.456 during respective year). Sowing depth of 10 cm resulted in significantly the highest plant height (82.2 cm), effective tillers/m2 (382.64), spike length (13.94 cm), spikelets/spike (16.44), grains/spike (38.21), grain weight/spike (1.90 g), 1,000-grain weight (46.24 g), grain yield (3.95 and 3.49 t/ha during both the years) and harvest index (0.456 and 0.443 during both the years).

Productivity, water use efficiency and soil properties of sugarcane as influenced by trash mulching and irrigation regimes under different planting systems in sandy loam soils

IntroductionIn the era of climate change, sugarcane used to face a problem associated with water shortage due to erratic rainfall patterns and lowered water tables. Improved water use efficiency using innovative crop management strategy is needed for sustainable sugarcane production. Trash mulching with different irrigation regimes can effectively modify the plant's hydrothermal micro-environment for increasing cane yield and water productivity.MethodsKeeping this in the background, a field experiment was conducted at Sugarcane Research Institute, RPCAU, Pusa, India, from 2016–17 to 2018–19 to investigate the effects of trash mulching and irrigation regimes on sugarcane productivity, water use efficiency (WUE) and soil properties in different planting systems. The field experiment comprised 12 treatments including four planting methods viz. conventional flat planting (CF; 75 cm row spacing) with trash mulching (6 t ha−1), CF planting (75 cm row spacing) without trash mulching (6 t ha−1), paired row trench (PT) planting (30: 120 cm row spacing) with trash mulching (6 t ha−1), PT planting (30: 120 cm row spacing) without trash mulching (6 t ha−1) and three irrigation schedules consisted of irrigation water (IW); cumulative pan evaporation (CPE) ratio of 0.60, 0.80, and 1.00 was laid out in strip plot design with three replications.Results and discussionThe cane yield (103.5 t ha−1) was found significantly higher in PT planting with trash mulching over the CF planting method with or without mulching. Concerning irrigation regimes using the IW/CPE ratio, it was found that the IW/CPE of 0.6 resulted in 16.9, 13.3% higher water-use efficiency, and 37.1, 40.7% higher water productivity over those under IW/CPE of 0.8, and 1.00, respectively. Furthermore, soil parameters like soil microbial biomass carbon (SMBC) and dehydrogenase activity were increased by 12.5, and 17.5 % due to trash mulching with trench planting as compared to those under conventional flat planting without mulching. The results suggest that planting sugarcane in paired rows and irrigation scheduling at 1.00 IW/CPE with the adoption of trash mulching practices is effective for increasing profitability by way of higher sugarcane productivity and water productivity and also in sustaining soil health.

Agronomic management: irrigation scheduling, mulching and integrated nutrient management influences growth, yields, quality, and economics of summer groundnut in a subtropical condition of India

In changing climate scenarios, practically sound and suitable agronomic management options are of utmost need for sustainable crop production. An experiment involving three irrigation scheduling, two mulching, and four integrated nutrient management (INM) treatments was undertaken for consecutive two years at the Research Farm of the Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India in a split-split plot design with three replicates. This study evaluated the effect of irrigation scheduling, mulching, and INM on the performance of summer groundnut under sub-tropical conditions. Irrigation scheduling, mulching, and INM had a significant influence on growth and developmental parameters, yield attributes, yields, shelling (%), harvest index, quality parameters, and economics. Scheduling irrigation at lower cumulative pan evaporation (CPE) hugely benefited crops through increased pod yield (8.3%) haulm yield (5%), kernel yield (8.4%), oil yield (8.6%), and net returns (12.7%) over higher CPE (100 mm). The use of paddy straw mulch enhanced pod yield, haulm yield, kernel yield, oil yield, and net returns by 8.2, 3.6, 8.3, 9.0, and 13.2%, respectively as compared to dust mulch. Among INM, 75% RDN (recommended dose of nitrogen) + 25% N (FYM) + 60 kg S (gypsum) adjudged significantly better and recorded higher biological yield (16%), net returns (39%), and B:C ratio (16.2%) than 100% RDN. It is concluded that scheduling irrigation at 60 mm CPE along with paddy straw mulch and 75% RDN + 25% N (FYM) + 60 kg S (gypsum) can be adopted for better yield and economics of summer groundnut under sub-tropical conditions.

Influence of Irrigation Scheduling on Physiological Growth Parameters and Yield of Wheat under Different Sowing Dates

Sowing time and irrigation play an important role to ensure higher production. Delay in sowing affects the growth and development of crop. Studying the effect of irrigation scheduling and sowing dates can provide a knowledge for improving production in late sowing conditions. A field experiment was conducted during the rabi season of 2020-21 at Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Madhya Pradesh to study the influence of irrigation scheduling on physiological growth parameters and yield of wheat under different sowing dates. The experiment comprised of 12 treatment combinations having three sowing dates, 3rd December, 18th December and 2nd January in the main-plot and four Irrigation Water/ Cumulative Pan Evaporation (IW/CPE) based irrigation scheduling, viz. 1.0, 0.9, 0.8 and 0.7 in the sub-plot was analyzed in split-plot design with three replications. The findings of present investigation revealed that the physiological growth parameters and yield were higher in 3rd December sown date. Among the irrigation scheduling, IW/CPE ratio 1.0 recorded significantly higher growth parameters and yield. The results of the present study conclude that adjusting sowing date with irrigation scheduling could assist in enhancing yield.

Root endophyte Piriformospora indica significantly affects mechanisms involved in mitigating drought stress in rice (Oryza sativa)

An experiment was conducted during the summer season of 2020 at College of Agriculture, Kerala Agricultural University, Vellayani to study the potential of a beneficial root endophyte Piriformospora indica Sav. Verma, Aj. Varma, Rexer G. Kost & P. Franken in mitigating drought stress in rice (Oryza sativa L.). The field experiment was undertaken in the lowland paddy fields with sandy clay loam texture in randomized block design. Treatments were Piriformospora indica colonized and non-colonized rice seedlings under 3 irrigation intervals of 30 mm, 35 mm and 40 mm cumulative pan evaporation and 2 irrigation depths of 1.5 cm and 3 cm. Plants colonized with P. indica significantly enhanced the yield attributes and root parameters. This symbiotic association alleviated the negative effects of drought stress by maintaining higher proline content (71.8 μmole/g) and relative leaf water content (74%) irrespective of interval and depth of irrigation. Colonization boosted the uptake of phosphorus and maintained higher chlorophyll stability index (79.20%). Yield attributes of P. indica colonized plants subjected to severe stress, were observed to be equivalent to those of non-colonized plants under moderate stress and association with the endophyte resulted in saving of 30 mm water and could help rice to combat drought stress. Higher phosphorus uptake enhanced the root volume (29.1cm3 ) under severe water stress facilitated improved nutrient uptake (10.6 kg/ ha) from deeper layers of soil for colonized plants compared to the control plants and acted as a mitigating mechanism against drought stress.

Effect of land configuration, irrigation regimes and nitrogen application on growth, yield and quality of Japanese mint (Mentha arvensis)

An experiment was conducted during summer season of 2016–17 at the Narendra Deva University of Agriculture and Technology, Faizabad, Uttar Pradesh, to study the effect of land configuration, irrigation regimes and nitrogen application on growth, yield and quality of Japanese mint (Mentha arvensis). The treatments consisted of 3 land configurations (flat-bed planting, ridge planting and raised-bed planting), 3 irrigation regimes 0.8 irrigation water: cumulative pan evaporation (IW: CPE), 1.0 IW: CPE and 1.2 IW: CPE ratio) and 3 nitrogen levels recommended dose of nitrogen [(RDN) 160 kg N/ha], 75% RDN (120 kg N/ha) and 125% RDN (200 kg N/ha)] in a splitplot design with 3 replications. Raised-bed planting recorded the maximum leaves/plant (188.8), plant fresh weight (1868 g/m2 ), leaf: stem ratio (1.84), herbage (1.80 t/ha) and oil yield (136.5 lit./ha) than the ridge and flat-bed planting. Irrigating the crop at an IW: CPE ratio of 1.2 resulted in the highest growth parameters, herb (1.71 t/ha) and oil yield (130.1 lit./ha) and quality parameters over other irrigation regimes. Significantly the maximum crop growth [leaves/plant (189.8), plant fresh weight (1784 g/m2), leaf: stem ratio (1.77)], herbage (1.71 t/ha) and oil yield (131.9 lit./ha); and quality parameters [carotenoid content (2.66 mg/g fresh weight), menthone content (6.23%), menthol content (72.0%) and oil content (0.77%)] were recorded with the application of 125% RDN over 75% RDN and it was at par with 100% RDN. This study indicated that planting on raised bed, irrigation at 1.2 IW: CPE ratio and the application of 125% RDN (200 kg N/ha) gave higher yield and quality of Japanese mint.

Assessing the Productivity and Economic Sustainability of Banana Cultivation under Diverse Colored Plastic Mulches in Western Maharashtra Region of India

Aims: Banana is a heavy feeder of the nutrients. It is therefore, essential to study the crop with respect to color plastic mulches and irrigation scheduling. In this study, the effect of various colored plastic mulches on the growth and quality parameters of banana crop along with its economic feasibility was assessed.
 Study Design: This experiment followed a Complete Randomized Block Design (CRBD) with nine treatments (T1 to T9), each with three replications.
 Place and Duration of Study: This study was carried out at Mahatma Phule Krishi Vidyapeeth, Rahuri, Maharashtra for the period of one year (crop cycle of banana).
 Methodology: Different color plastic mulches in combination with varying irrigation schedule were evaluated for growth and yield of banana crop. Various growth parameters of banana crop, yield, micrometeorological parameters, water use efficiency and cost economics of banana production were evaluated for the different treatments.
 Results: The highest banana yield recorded was 84.45 tons per hectare, and this was achieved using silver-black plastic mulch in conjunction with daily drip irrigation set at 48% of the Pan Evaporation (Ep) rate, referred to as treatment T3. Treatment T3 led to 37% increase in banana yield compared to surface irrigation with 1.00 Irrigation Water to Cumulative Pan Evaporation (IW/CPE) ratio (treatment T9). The seasonal water requirement for banana cultivation with treatment T3 amounted to 1015 mm, resulting in an impressive water use efficiency of 83.18 kg ha-1 mm-1. Normalized Difference Vegetation Index (NDVI) values exhibited a range from 0.3895 during the initial growth stage of the banana to 0.8918 at the peak growth stage.
 Conclusion: From an economic perspective, the utilization of silver-black plastic mulch emerged as the best choice among all treatments, boasting the highest benefit to cost ratio of 2.34 and yielding the maximum net income of ₹ 3, 86,286 per hectare.

Interaction of cultivars of Cymbopogon species with the levels of irrigation frequencies on the variability of secondary metabolite production, essential oil productivity and economics in drought prone Bundelkhand region, India

In the present study, three cultivars of Cymbopogon species viz., Lemongrass var. CKP-25, Himrosa var. IIIM(J)CK-10 and Jamarosa var. RRL(J)CN-5 were assessed with five levels of irrigation frequencies viz., 0.20 IW, 0.40 IW, 0.60 IW, 0.80 IW and 1.00 IW, in three consecutive years (2019-2022). In the study, irrigation was scheduled at 5 cm depth and performed as per the IW: CPE ratio. The amount of water was applied as per the levels of irrigation frequency from lower to higher and to meet the ratio of cumulative pan evaporation (CPE). Furthermore, increase in the levels of irrigation frequency increased the essential oil yield. Interaction among the cultivars of Cymbopogon species with the different levels of irrigation frequencies, Lemongrass var. CKP-25 proved significantly the highest essential oil yield (209.97, 389.12 and 406.57 kg ha−1) during 1st, 2nd and 3rd year, respectively. Similarly, in 2nd and 3rd years the net returns were found to be highest in Jamarosa var. RRL(J)CN-5 (Rs. 454627.00 and 502990.30 ha−1), respectively at same levels of irrigation frequency. The benefit: cost ratio was found to be superior with treatment receiving irrigation at 1.00 IW. However, percentage of essential oil content, secondary metabolite production viz., Lemongrass, citral (citral a + citral b) content percentage (82.47 ± 2.12), Himrosa and Jamrosa, geraniol and geranyl acetate percentage (76.23± 1.46 and 8.49 ± 1.03) and (61.12 ± 1.58 and 25.88 ± 1.11), respectively, highest at 0.20 & 0.40 IW, while both decreases at higher levels of irrigation frequency (1.00 IW) in all the three consecutive years.

Effects of Different Irrigation Regimes and Genotypes on Yield Contributing Parameters of Potato (Solanum Tuberosum L.) Under Chhattisgarh, India

The field experiment was conducted at the Horticultural Research Farm, College of Agriculture, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh, India during Rabi 2018-19 in Split plot Design with four level of irrigation regimes and four potato genotypes. The irrigation treatments were allotted in the main plot while, potato genotypes allotted in the sub-plots. At 75 days after planting (DAP) and 90 days after planting (DAP), the various yield contributing parameters were affected significantly by the different irrigation regimes except the plant emergence and number of shoots/plant. The number of shoots/plant, number of total leaves/plant, fresh weight of tubers/plant (g), total number of tuber/plant and harvest index (%) were significantly affected by the different irrigation regimes and potato genotypes. The plant with irrigation at 25 mm cumulative pan evaporation (CPE) produced the maximum plant height, number of shoots/plant, number of total leaves/plant, number of tubers/plant, fresh weight/plant and harvest index at 75 DAP and 90 DAP, respectively. The potato genotype AICRP-P-38 gave the highest fresh weight of tuber/ plant, number of tubers/plant and harvest index at 75 DAP and 90 DAP, respectively. Bangladesh J. Bot. 52(1): 211-216, 2023 (March)

Standardizing Drip Irrigation Scheduling and NPK Levels on Economics and Energy use of Mentha (Mentha arvensis) Crop in Tarai Regions of Uttarakhand

To standardize the scheduling of drip irrigation and NPK levels on yield, economics and energy use of mentha crop, this field study was executed at G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand), India in the Norman E. Borlaug Crop Research center during the spring season of 2017. This experiment was performed in Factorial RBD having three replications. Three drip irrigation scheduling levels, 75%, 100% and 125% based on cumulative pan evaporation (CPE) loss with one control as a conventional flood and three NPK levels, 75%, 100% and 125% are taken as treatments. Experimental data conclude that drip irrigation CPE and NPK levels at 125% recorded the maximum fresh herbage (29699 and 30027 kg/ha), oil yield (260 and 274 kg/ha) and farm economics. Further the highest oil content was recorded with 125% NPK level (0.92%) but in case of CPE level, it is highest with 75% CPE (0.94%). Highest total energy input and output recorded with 125% CPE and 125% NPK levels, being 18674 and 18383 MJ/ha (input), 51988 MJ/ha and 55099 MJ/ha (output), respectively. Energy use efficiency and energy productivity increase with increase in irrigation levels and NPK dose, being highest with 125% CPE and 125% NPK dose. Again Drip irrigation and NPK level of 125% recorded maximum energy intensiveness of 0.24 MJ/Rs and 0.23 MJ/Rs and net energy gain of 33604 MJ/ha and 36425 MJ/ha, respectively.

Interactive effect of nitrogen and irrigation on evapotranspiration, growth, yield and water productivity of subsurface drip‐irrigated spring maize: Field and simulation studies

AbstractIn northwest India, spring maize water productivity can be increased with subsurface drip irrigation. Therefore, a field experiment was conducted in a split‐plot design for 2 years to assess the effect of three nitrogen levels (125 [N1], 100 [N2] and 75 [N3] kg N ha−1) in the main plots and seven irrigation regimes (six subsurface and one surface drip) in the subplots on water productivity of spring maize. Subsurface drip irrigation was applied at 100%, 80% and 60% cumulative pan evaporation on alternate days (I1, I3 and I5) and at 2‐day intervals (I2, I4 and I6) along with surface drip irrigation at 80% pan evaporation on alternate days (I7). The evapotranspiration (ET), transpiration (T), dry matter accumulation (DMA), leaf area index (LAI), root mass density (RMD), N uptake and grain yield were at par in N1 and N2 but significantly higher than in N3. T, DMA, LAI, RMD, grain N uptake and grain yield were at par in I1, I2, I3 and I7 but significantly higher than in I4, I5 and I6. The real water productivity was at par in N1I1, N1I3 and N2I3 but significantly higher than other interactive combinations. The CERES‐Maize model satisfactorily simulated crop biomass, grain yield, LAI, ET and transpiration.

Effect of irrigation schedules and hydrogel levels on yield and economics of blond psyllium (Plantago ovata)

A field experiment was conducted during the winter (rabi) season of 2018–19 and 2019–20 at Rajasthan College of Agriculture, Maharana Pratap University of Agriculture and Technology, Udaipur, Rajasthan to study the effect of hydrogel levels under different irrigation schedules on blond psyllium (Plantago ovata Forssk.). The field experiment was conducted in a split-plot design, comprising of 4 irrigation schedule, viz. irrigation water (IW) : cumulative pan evaporation (CPE) ratio 0.20, 0.30, 0.40 and 0.50 in main plots and 4 hydrogel levels, viz. control, 2.5, 5.0 and 7.5 kg/ha in subplots, combinedly having 16 treatment combinations, which were replicated 4 times. The results revealed that an application of irrigation at IW : CPE ratio of 0.50 had significant effect on yield attributes, viz. spike length (3.67 cm), seeds/spike (76.05), test weight (1.744 gm) and yield seed (0.767 t/ha), straw (2.609 t/ha) and biological yield (3.376 t/ha) which was at par with IW : CPE ratio 0.40 and both these ratios significantly improved the yield over IW : CPE ratio of 0.30 and 0.20 during both years. Both IW : CPE ratio 0.40 and 0.50 fetched highest net returns of `38,658 and 39,118/ha, with benefit: cost ratio 1.05 and 1.04 respectively. Application of 7.5 kg/ha hydrogel resulted in the highest spike length (3.66 cm), seeds/spike (74.83), test weight (1.766 gm), seed (0.767 t/ha), straw (2.555 t/ha) and biological yield (3.322 t/ha) and was at par with application of 5.0 kg/ha hydrogel and both these levels significantly enhanced blond psyllium crop yield over application of 2.5 kg/ha hydrogel and the control during both the years. Application of hydrogel at 5.0 kg/ha significantly enhanced net returns (`39,281/ha) and benefit: cost ratio (1.06) as compared to application of 2.5 kg/ha hydrogel and the control; however, further increase in hydrogel level to 7.5 kg/ha caused significant reduction net returns (`37,726/ ha) and benefit: cost ratio (0.96) as compared to application of 5.0 kg/ha hydrogel during both years and pooled analysis.

Promising Bioregulators for Higher Water Productivity and Oil Quality of Chia under Deficit Irrigation in Semiarid Regions.

Appropriate water management practices are essential for the successful cultivation of chia in water-scarce situations of semiarid regions. This is highly essential when new crops such as chia are introduced for ensuring diversity and water saving. Therefore, field trials (2020-21 and 2021-22) were conducted to understand the impact of deficit irrigation and bioregulators (BRs) on the seed yield, water productivity, and oil quality of chia. The effect of foliar application of BRs such as thiourea (TU; 400 ppm), salicylic acid (SA; 1.0 mM), potassium nitrate (KN; 0.15%), potassium silicate (KS; 100 ppm), kaolin (KO; 5%), and sodium benzoate (SB; 200 ppm) were monitored at different levels of irrigation: 100 (I100), 75 (I75), 50 (I50), and 25 (I25) percent of cumulative pan evaporation (CPE). Deficit irrigation at I25, I50, and I75 led to 55.3, 20.1, and 3.3% reductions in seed yield; 42.5, 22.5, and 4.2% in oil yield; and 58.9, 24.5, and 5.7% in omega-3 yield, respectively, relative to I100. Bioregulators could reduce the adverse impact of water deficit stress on seed, oil, and omega-3 yield. However, their beneficial effect was more conspicuous under mild water stress (I75), as revealed by higher seed yield (4.3-6.9%), oil yield (4.4-7.1%), and omega-3 yield (4.7-8.5%) over control (I100 + no BRs). Further, BRs (KN, TU, and SA) maintained oil quality in terms of linolenic acid and polyunsaturated fatty acid contents, even under mild stress (I75). Foliar application of KN, TU, and SA could save water to an extent of 36-40%. Therefore, the adverse impact of deficit irrigation on seed, oil, and omega-3 yields of chia could be minimized using BRs such as KN, TU, and SA, which can also contribute to improved water productivity.

Enhancing yield of lettuce through irrigation and nitrogen management in a subtropical Inceptisol

Abstract To address the dearth of management of lettuce in the Indo-Gangetic plains, field experiment was conducted on a sandy loam Inceptisol for optimizing the irrigation, nitrogen requirement and economics of lettuce for three years. Four irrigation levels (conventional, I1 and irrigation at 0.6, 0.8, 1.0 irrigation water to cumulative pan evaporation (IW/CPE) ratio, as I2, I3 and I4) and three nitrogen management (100% recommended dose of N i.e., RDN as inorganic, N1; 50:50% RDN as inorganic: vermicompost, N2 and 100% RDN as vermicompost, N3) was laid out in thrice replicated split plot design. All the major physiological characteristics like plant height, number of leaves, average head diameter was improved with I4, N2 and their interaction (I4N2). Maximum average head yield (10.6 t ha−1) was obtained with I4 and I3, 10.5 t ha−1 for N2, while I4N2 yielded 11.3 t ha−1. Maximum water productivity (11.8 kg m−3) was obtained under I2N2. A strong non-linear relationship was detected between yield with irrigation water applied (). Higher soil moisture extraction (80.2%) in top 0–30 cm and lower (19.8%) for 30–45 cm depth and maximum leaf dry matter yield, nutrient concentrations and uptake was found with I4N2 and I3N2. The moderate deficit irrigation and optimum nutrient at I3N2 was found best for optimizing yield, higher water productivity, nitrogen economy and monetary returns of lettuce.

Scheduling of Irrigation Based on IW/CPE for Aerobic Rice – A Review

The scheduling of irrigation according to the ratio between irrigation water depth (IW) and cumulative pan evaporation (CPE) rate for aerobic rice. During these days, the shortage of water resources is increasing continually due to climate change. It has led to the adaptation of rice farming under aerobic conditions. This saves irrigation water, labour, eliminates puddling, reduces seepage, percolation losses, and methane emissions. Aerobic rice cultivars produce higher plant growth, physiological, root growth, yield, water use efficiency, productivity, and soil nutrient uptake under different (0.6, 0.8, 1.0, 1.2, 1.4, 1.5, 2, and 2.5) IW/ CPE ratios. Under these irrigation schedules, the yield of rice in aerobic soil is recorded at between 4.5 and 7.1 t ha-1 and the water use efficiency is from 25 to 70 kg ha-1. However, the decline in yield or even crop failure under continuous monocropping, weeds, nematode problems, and aerobic rice micronutrient deficiency Our important findings in aerobic rice are: (1) Scheduling of irrigation based on various IW/ CPE ratios recorded the higher rice plant height, number of tillers hill-1, dry matter production, leaf area index, crop growth rate, relative growth rate, root length, productive tillers, number of grains panicle-1, number of filled grain panicle-1, total number of grains panicle-1, test weight and yield; (2) The last 15 years of aerobic rice research findings focused on irrigation scheduling by IW/CPE ratio for driving economic water use; and (3) nutrient uptake increased with irrigation at more than 1.0 IW/CPE ratio with depth of 5 cm irrigation water. Declining water availability due to climate change makes it necessary to conduct more research on irrigation scheduling in rice crops in order to increase yield and water use efficiency.