4. CROP AND NATURAL RESOURCE MANAGEMENT FOR SUSTAINABLE ENVIRONMENT
4.3 WATER MANAGEMENT
Soil test based fertilizer prescription equations for targeted yield of mustard
Fertilization
programme Fertilizer prescription equation
NPS alone FN = 10.90T – 0.62 SN FP = 1.94T – 1.0 SP FS = 2.64T – 0.88 SS NPS + FYM FN = 10.90T – 0.62 SN – 0. 20
FYM
FP = 1.94T – 1.0 SP – 0.04 FYM
FS = 2.64T – 0.88 SS – 0.06 FYM
FN, FP and FK – fertilizer N, P and K in kgha-1, respec- tively; T- target yield in q/ha; SN, SP and SK– alkaline KMnO4 – N, Olsen’s-P and Neutral Normal Ammonium Acetate K in kgha-1, respectively; FYM represents dose of farmyard manure (t/ha-1),
4.2.13 Zinc dynamics under long-term fertilization and manuring in maize-wheat system
Result revealed that continuous application of NPK+Zn increased the water soluble plus exchangeable, carbonate bound, oxide bound, residual and total Zn, whereas NPK+FYM enriched the organically bound Zn. Application NPK+FYM reduced the carbonate and oxide bound Zn as compared to other treatments. Residual Zn remained unaffected due to long-term fertilization and manuring, except NPK+Zn. Adsorption maxima and affinity coefficient of Langmuir equation for Zn adsorption followed the order: Control = N alone ˃ NP = NPK ˃ 150% NPK ˃ NPK+FYM = NPK+Zn. The cumulative desorption of adsorbed Zn during four consecutive steps was highest in soil under NPK+FYM (55.3 µg g-1) and lowest in control (18.3 µg g-1). Application of FYM could reduce the affinity of Zn for different soil constituents in soil, which in turn enhanced its availability.
4.2.14 Nutrient management protocols and organic C mineralization under CA
Application of 75 kg N ha-1 as basal along with 4 t crop residue (CR) ha-1 and GS-based N use (02 split)
under 25% available soil moisture depletion (ASMD) is the most efficient N management protocol during the initial years under CA. After 3 years of continuous CA, basal N application can be omitted under irrigation at 25% ASMD and GS-based split N application. Similarly, application of 4 t CR ha-1 along with only 40 kg P2O5 ha-1, phosphorus solubilizing bacteria (PSB and AM) had equal yield to the plots receiving 4 t CR ha-1 and 80 kg P2O5 ha-1 indicating 50% P fertilizer savings under CA based system. Application of 4 t CR ha-1 along with only 30 kg K2O ha-1and KSB was also equal to the plots receiving 4 t CR ha-1 and 60 kg K2O ha-1 in terms of system productivity indicating 50% K fertilizer savings under CA.
Soil carbon mineralization study carried out at two temperature regimes (25 and 35 °C) using the soils from 8-year-old CA based system indicated that the highest cumulative carbon (Ct) mineralization occurred in plots having triple zero tillage with residue which was also significantly higher as compared to triple zero tillage without residue and control (no- N,P, K).
besides calculated thermal indices, which would assist the decision on scheduling irrigation. The developed device was calibrated for soil moisture sensor at 0-15 cm depth and compared with the gravimetric method resulted in coefficient of determination (R2) of 0.84.
Besides this, a digital water measuring device was developed to measure irrigation water supplied in open field channels of canal command. The device consisted of a modified flume and the digital sensing system with display unit to measure the flow depth, discharge and volume of water supplied to cropped field. Designed device was standardized and calibrated in the hydraulic flume testing facility to develop the depth and discharge rating curve. The fitted equation of the rating curve was embedded in the digital sensing system through programmed code to display the flow depth and subsequent discharge rate.
Further, the fabricated device was tested in the open channel and the measured discharge rate was in close agreement with the observed discharge corroborated with prediction error statistics R2 (0.99) and Mean Absolute Percentage Error (4.3).
4.3.3 Water and nitrogen distribution in soil under drip fertigation in lettuce
Results indicated that the available nitrogen content in soil was higher near emitter in upper surface (0-15 cm) in all the treatments and reduced with
distance and depth from emitter. Urea ammonium nitrate (UAN) and calcium nitrate (CN) applied plots showed higher nitrogen content after 24 hours of fertigation. Soil moisture content was found to be higher near emitter as compared to deeper points and water content reduced on outer surfaces of wetting front. The highest yield was recorded in plots fertilized with UAN at 60 kg Nha-1 (37.6 t ha-1) followed by UAN at 40 kg N ha-1 (36.4 t ha-1), NCU at 60 kg N ha-1 (34.4 t ha-1) and NCU at 40 kg N ha-1 (32.9 t ha-1), respectively.
It was observed that application of UAN led to 25 - 30 percent of nitrogen saving with same yield.
4.3.4 Spatio-temporal evaluation of water quality in water harvesting structures in Nuh, Haryana
The mean pH, EC, turbidity, calcium and magnesium, chloride, sodium, potassium, SAR, and TDS of water were within the permissible limit in Nuh block, Mewat, Haryana. However, carbonate, bicarbonate and RSC contents were above the permissible limits. Water harvesting structures (WHSs) fed with R+C+S, showed substantially higher BOD. Out of the 80 WHSs, 75 WHSs were listed under medium category of suitability during pre-monsoon and 78 WHSs each during monsoon and post-monsoon period. Overall, the majority of the WHSs in Nuh block were moderately suitable for irrigation. It can
Spatio-temporal variability of IWQI in Nuh block, Mewat, Haryana
be recommended to avoid direct inflow of village sewage and canal water to WHS by installing suitable eco-friendly water treatment plant, desilting of ponds besides adoption of integrated farming system approachfor improving water quality.
4.3.5 Composite hydrologic index for groundwater recharge in Betwa river basin
Composite hydrologic indices (CHI) were developed for evaluating the recharge potential in the Betwa river basin. The prospect of groundwater recharge was assessed in relation to soil type, slope, rainfall runoff ratio and ET. Groundwater recharge potential zone of the basin can be divided into four grades, viz. very good, good, moderate and low based on the four factors that affect groundwater recharge.
Very good ground water with high infiltration rate than clay and clay loam soil. Composite hydrologic indices (CHI) for the study area were found to vary from 0.01 to 1. The suitable site for water harvesting structure in each Hydrologic Response Unit (HRU) having possibilities to increase the groundwater level is shown.
Suitable sites of targeting water harvesting structures in Betwa basin
4.3.6 Spatio-temporal variability of water table depth in Pitamberpur watershed, U.P.
Ground water recharge from selected rainwater harvesting structures in the Pitamberpur watershed in the J. P Nagar of Uttar Pradesh, were estimated and the spatio-temporal variability map was generated using ArcGIS.
a. 2010 (Pre and Post Monsoon)
b. 2017 (Pre and Post Monsoon)
Spatio-temporal variability of water table depth in Pitamberpur Watershed, UP during 2010 and 2017
4.3.7 Evaluation of CERES-wheat model of DSSAT under changing climate
CERES-wheat model of DSSAT was calibrated and validated using data of wheat cultivar HD-2967 with three dates of sowing and five irrigation. The validated model performance was in line with the observed grain yield corroborated by the root mean square error (RMSE) of 0.035 and degree of agreement (d) 0.98 under five irrigation regimes. Further the validated model indicated yield decline by 6 to 22% and 8 to 16%
with increase in temperature from 1 to 30C under full and deficit irrigation regimes, respectively. Whereas, reduction in temperature from -1 to -3⁰C showed an increase in yield by 10 to 28% and 7 to 20% under full and deficit irrigation, respectively. Similarly, the increase in solar radiation from +1 to +3 MJm-2d-1 resulted in yield increase by 5 to 12% and 3 to 7% and
decline in same range resulted in yield decrease by 7 to 24% and 6 to 17.5% under full and deficit irrigation, respectively. Further, effect of enhanced level of CO2 from 500 to 800 ppm simulated increase in yield by 7 to 24% and 6 to 19% under irrigated and deficit irrigation, respectively. Moreover, the combined effect of increasing temperature and CO2 concentration revealed that highest yield was obtained at higher level of CO2 concentration with 10C increase in temperature.
But, rise in temperature by +30C, besides doubled CO2 concentration of 800 ppm resulted in only 2% increase of yield under full irrigation and 4.4% yield decline under deficit irrigation.
4.3.8 Multi-metal reduction potential of the macrophyte consortia in up-scaled mesocosmic wetlands
The metal sequestration potential of 4-shortlisted macrophyte combinations [viz. Typha latifolia + Phragmites karka (TA); Phragmites karka + Arundo donax (PA); Arundo donax + Typha latifolia (AT) and Vetiver zizinoids + Typha latifolia (VT)] from metal spiked waste water of IARI was compared in the up-scaled experimental mesocosms wetlands.
Investigations revealed non-significant differences in their metal reduction potentials. However, long term data indicated Typha (T) and Phragmites (P) to be out- competing the other macrophytes (viz. Arundo and Vachha), in each of the aforementioned mixed culture macrocosmic systems. It was observed that layered planting of typha instead of mixed planting is suitable to harness their full multi-metal reduction potential.
Besides this, 100 microbial strains were isolated from the aforementioned mixed cultured multi-metal spiked mesocosms. These were subjected to minimum inhibitory concentration (MIC) analysis for Ni (10-50 ppm), Cr (10-300 ppm) and Pb (10-300 ppm) besides assessment for their multi-metal reduction potential (at 10 ppm Ni, Cr, Pb concentrations). Analysis assisted in shortlisting of 21 promising bacterial isolates for remediating multi-metal polluted wastewaters through bio-augmentation of wetland ecosystem.
4.3.9 Standardization of chitosan and calcium alginate bead making technology for heavy metal reduction from wastewaters
Five different bead making protocols which are generally used for making chitosan based beads were investigated and the developed beads were evaluated for their size, strength, functional group and structure based on the Fourier Transformed Infrared Spectroscopy (FTIR) and X-Ray diffraction (XRD) analysis. Out of tested five different bead making protocols, only the one using lingo-sulphonate was found to be of any practical significance. Moreover, XRD analysis of the beads developed through this protocol indicated a good cross linkage of the chitosan and lingo-sulphonates. FTIR analysis of the beads, on the other hand, confirmed the presence of hydroxyl, amine and the amide groups which can act as polymeric chelating ligands for the chemi-sorption of heavy metals. Studies on the use of the calcium alginate alone and the a for ementioned standardized chitosan coated calcium alginate beads for their heavy metal remediation and regeneration potential from saline and non-saline waters were also successfully designed and implemented.
4.3.10 Essential oil yield and quality of lemongrass under waste water irrigation
Untreated wastewater contained 17.5, 3.97 and 14.8 mg L-1 and treated had 7.5, 1.06 and 5.45 mg L-1 of N, P and K, respectively. Total herbage of lemon grass irrigated with untreated wastewater was the maximum and 15% higher as compared to groundwater. Similarly, essential oil yield produced by using untreated wastewater was 11 and 16% higher compared to treated wastewater and groundwater irrigation, respectively.
As compared to untreated wastewater, the treated wastewater has reduced Ni and Pb accumulation by 22-23%. Soil organic carbon and available N, P, Ni and Pb contents of soil were also more with untreated wastewater irrigation as compared to groundwater irrigated soil. Heavy metal concentrations in essential oil were not detectable indicating that its presence in oil is not influenced either by water quality or nutrient doses.
4.3.11 Performance of new wheat genotypes under restricted irrigation conditions
Five wheat genotypes, viz., DDW 47, DBW 110, HI 8627, MP 3288 and UAS 466 were evaluated at different irrigation schedules under limited irrigation conditions. Irrigation at CRI + boot leaf stage had significantly higher grain (3.63 t ha-1) and biological yields (8.49 t ha-1) over other irrigation scheduling.
Genotypes, MP 3288 recorded the maximum grain and biological yield (3.09 t ha-1 and 7.11 t ha-1, respectively) which was significantly at par with HI 8627 but significantly higher over rest of the genotypes.