Agro-climatic classification in India

In the present study, principal component analysis has been applied to agroclimatic variables for delineating India into homogeneous agroclimatic zones for kharif crops. The vaTiates chosen were soil moisture, water need of the crops, number of rainy days and radiation. Spatial variability of some of these factors has been discussed. Vector 1 and vector 2 were obtained for each of the three separate sets of the variates and plotted to obtain grid maps. Through a process of successive superimposition of these maps, agro-climatic zones have been obtained.

Stability Analysis of Rice Hybrids for Grain Yield in Telangana through AMMI and GGE Bi-plot Model

An investigation was carried out on fifteen rice genotypes to identify stable rice hybrids across six different agroclimatic zones in Telangana state using AMMI and GGE bi-plot analyses during July to November, 2020. Analysis of variance clearly showed that environments contributed highest (65.47%) in total sum of squares followed by genotypes×environments (21.19%) indicating very greater role played by environments and their interactions in realizing final grain yield. AMMI analysis revealed that rice hybrids viz., RNRH 39 (G6), 27P31 (G14) and RNRH 15 (G1) were recorded higher mean grain yield with positive IPCA1 scores. The hybrids, JGLH 275 (G11) and JGLH 365 (G15) were plotted near to zero IPCA1 axis indicating that these hybrids are relatively more stable across locations. GGE bi-plot genotype view depicts that the hybrids, JGLH 365 (G15) and US 314 (G8) were inside the first concentric circle and found to be more stable across environments. GGE bi-plot environment view showed that Rudrur (E4) location was the most ideal environment. However, Warangal (E6) and Jagtial (E1) locations were poor and most discriminating. Depending on dispersion of environments in different directions, six locations were partitioned into three mega zones as first zone comprised of four locations viz., Kunaram (E2), Kampasagar (E3), Rudrur (E4) and Rajendranagar (E5) whereas highly dispersed Jagtial (E1) and Warangal (E6) were identified as two separate mega environments. The bi-plot view identified that 27P31 (G14), JGL 24423 (G2) and RNRH 39 (G6) were the best performing genotypes in first zone comprising four locations.

A Critical Analysis of Effect of Projected Temperature and Rainfall for Differential Sowing of Maize Cultivars Under RCP4.5 and RCP6.0 Scenarios for Punjab

A simulation study was conducted for two cultivars of maize (PMH1 and PMH2) in four agroclimatic zones of Punjab state of India where climate change depicts a consistent rise in temperature and increased variability in amount and distribution of rainfall. The yield assessment was performed for four agroclimatic zones of Punjab comprising of seven locations because variability in temperature rise and rainfall existed from location to location. Corrected ensemble model weather data (temperature and rainfall) for RCP4.5 and RCP6.0 was used as an input in the calibrated and validated CERES-Maize model and yield was simulated for a period of 70 years. The simulated yield for near as well as far-future was statistically assessed to understand the yield trend in Punjab under current dates of sowing and the results indicated a strong negative correlation between the yield and the weather parameters under the two scenarios at the considered four agroclimatic zones of Punjab. An increase in maximum and minimum temperature was observed ranging 0-4°C and 3-8°C, respectively at all the agroclimatic zones except Faridkot (zone V) where the increase in minimum temperature was observed by 0-3°C during the crop growth season while the rainfall variability ranged from 200-800mm under both the scenarios. At agroclimatic zone II and zone III similar results were obtained with higher yields at later dates of sowing and the rainfall at agroclimatic zone III was higher under RCP6.0 (300-600mm) while the yields for agroclimatic zone IV and V (Abohar) with rainfall variation of 270-450mm and 200-400mm, respectively showed no yield increment. Maize at Faridkot performed well with higher yields at early sowing dates. Among the two cultivars PMH1 showed more high yield years than PMH2 for most of the years. The yield under differential sowing dates showed the first fortnight of June and end June to be the best sowing dates for most of the locations as the yield for these dates were higher for most of the years. Thus, the study can be further applied to decide the future sowing window of maize for the agricultural state like Punjab.

Phenophase wise study of parameters controlling water requirement of soybean crop [Glycine max (L.) Merr.] at various agroclimatic zones

Soybean is a major kharif season crop in parts of M.P., U.P., Gujarat, Punjab and Haryana,Maharashtra, Rajasthan, A.P. and Chattisgarh. The present work was undertaken to study the parameters controllingwater requirement of the crop at various phenophases in soybean growing 8 ET- stations (viz., Akola, Bangalore,Banswara, Dharwar, New Delhi, Parbhani, ICRISAT and Rahuri) in various agroclimatic zones. Eight phenophases of thecrop (viz., germination, seedling, vegetative, active vegetative, flowering, pod formation, pod maturity and harvesting)were identified. The data were collected for latest available 3 to 5 years and the mean values were analysed. The study onsoybean crop revealed that the mean total water requirement demand of the crop varied from 294.7 to 559.2 mm indifferent soybean growing ET stations. The ET demand reached the peak mostly at active vegetative stage (which was19.0 to 25.6 % of the total ET demand, at various locations). The computed best – fit ET curves provide ET demand ofthe crop at any point of the phenophases for the specific location. The rainfall during study period was mostly sufficientto meet the crop specific ET demand at various phenophaes of soybean crop. Abundant soil moisture supported goodvegetation cover. The mean Kc value varied widely from 0.61 to 0.98 among different stations studied, which reachedtheir peak mostly at active vegetative to flowering stages, where the values were even more than 1 in most of thosephenophases except 3 stations. The mean soybean crop yield and productivity varied widely agroclimatic zone wise. Thesoybean yield varied from 981.0 kg/ha to 2530.6 kg/ha, while productivity per day varied from 9.0 kg/ha/day to 23.2kg/ha/day. The WUE of the crop laid between 2.1 kg/ha/mm to 6.0 kg/ha /mm at various locations.

A critical study on parameters controlling water requirement or wheat Triticum aestivum L.) at various growth stages in ten different agroclimatic zones

ABSTRACT. The parameters controlling water requirement of wheat and its crop data, at various critical growth stages from ten different agroclimatic zones for five years. were collected and analysed. The study revealed that the total CU-demand for wheat crop in different wheat growing zones varied from 160 to 465 mm of water. In most of the zones, peak CU-demand were either at milk stage (21.0% of the total CU demand or at different stages (19.5% of the total CU-demand). Rabi season rainfall was not sufficient to meet the crop C.U-demand at different growth stages. The soil moisture study revealed that its depletion started around tillering stage indicating thereby, need for irrigation water beyond that stale. Computed average Kc, values (throughout the crop growth period) varied from 0.36 to 1.05 in different agroclimatic zones. Growth stage-wise K, values at or after elongation stage even exceeded one. Wheat yield in various agroclimatic zone varied from 1900 to 4800 kg/ha with the average productivity of 17 to 26 kg/ha/day. The WUE of the crop in different zones lay between 5 to 17 kg of grain/ha/mm of water. Depending upon this study wheat growing areas were divided into six zones.

Peculiarities of acid-base properties of peat formed in various agroclimatic zones of the Altai mountainous region

The results of the study of acid-base indicators of peat in the Altai mountainous region are presented. The natural factors that in the aggregate determine the peculiarities of the physico-chemical properties of mountain peat of different agro-climatic zones of the Altai Mountains have been revealed. The variation in the acid values, total absorbed bases, adsorption capacity and the degree of saturation of raised-bog, transitional, fen peat, the number of exchangeable ions Ca2+ and Mg2+ has been estimated. The interrelation among these indicators has been presented. For the first time, regression equations of the relationship between exchangeable acidity pHKC1 and the degree of peat base saturation V, between total absorbed bases S and the degree of peat base saturation V have been obtained using nonlinear regression analysis. The adequacy and stability of the developed models have been verified. The calculated mean errors of approximation of regression models characterise the high accuracy of the forecast and are indicative of a good selection of models for the initial data.

Regulation of Phosphorus and Zinc Uptake in Relation to Arbuscular Mycorrhizal Fungi for Better Maize Growth

Zinc (Zn) is an important micronutrient for plants, whose deficiency in alkaline soils creates hurdles in the achievement of optimum crop growth. Moreover, overuse of phosphorus (P) fertilizers often causes Zn immobilization in the soil. The employment of arbuscular mycorrhizal fungi (AMF) could be potentially environmentally friendly technology in this regard. Therefore, a pot experiment was conducted to assess the beneficial role of AMF (Glomus species) on maize under low and high P and Zn levels. Seven levels of Zn (0, 20, 40, 60, 80, 100 and 120 mg Zn kg−1 soil ZnSO4·7H2O) and three levels of P (0, 14.5, 29 and 58 kg ac−1 as single superphosphate) were applied with (M+) and without AMF (M−). The results showed that a high application rate of Zn (100 and 120 mg Zn kg−1 soil) restricted P translocation in plants and vice versa. Moreover, the nutritional status of mycorrhizal plants (AM) was better than non-mycorrhizal (NM) plants. AM plants showed a maximum positive response at 20 mg Zn kg−1 soil, or 29 kg P ac−1. In response to 20 mg Zn kg−1 soil, root colonization was maximum, which enhanced the maize nutrient concentration in shoots. In conclusion, AMF inoculation (M+) with P (29 kg ac−1) and Zn (20 mg kg−1) is efficacious for improving maize’s growth and nutrition. More investigations are suggested at the field level under different agroclimatic zones to ascertain whether P (29 kg ac−1) or Zn (20 mg kg−1) with AMF is the best treatment for maize growth optimization.

Potassium mobilization and plant growth promotion by soil bacteria isolated from different agroclimatic zones of Odisha, India

<p class="042abstractstekst"><span lang="EN-US">Potassium is essential for plant metabolism; improves immunity to stress and increase crop productivity. Soil contains insoluble form of potassium, which is unavailable for plant absorption. Potash mobilizing bacteria (KMB) solubilise complex potassium and make it available to plant. KMB with plant growth promoting (PGP) traits could enhance growth and crop productivity. Here we attempt to screen KMBs with PGP traits from different agroclimatic zones of Odisha and study dynamics of potassium in soil. Isolation of KMB and determination of PGP traits was performed with standard protocols. Pot culture experiment was aimed to study their effect on sunflower crop. Available soil potassium was quantified using inductively coupled plasma-optical emission spectrometry (ICP-OES). Thirty KMBs were isolated from different agro-climatic zones of Odisha, out of which 6 isolates exhibited maximum PGP traits. Moreover, after adding inoculums the available soil potassium decreased over 0 to 30 days as compared to control, with increase in shoot length. T7 (consortium) reported maximum (144 %) increase in shoot length. Available soil potassium content decreased with increase in time. A maximum decrease was reported in T7 (26.31 %), suggesting potassium accumulation by plant.</span></p>

Agroclimatic zonation of Tigray region of Ethiopia based on aridity index and traditional agro-climatic zones

The aim of this study was to identify the agroclimatic zones of Tigray region based on aridity index and traditional agroclimatic zone using 37-year (1981-2017) spatial climate data downloaded for Tigray region from Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) for rainfall and from Enhancing National Climate Services (ENACTS) data for temperature. Arc map 10.3 was used for mapping of all climatic variables and zonation of agro-climatic zones. Potential evapotranspiration (PET) was computed based on Hargreaves formula and the aridity index was computed. Besides, the digital elevation model was downloaded from ASTER data. The aridity map of Tigray divided into three index zones (0.03-0.2, 0.2–0.5 and 0.5–0.65) and five traditional agro-climate zones (<1500,1500-2000,2000- 2500, 2500-3000, >3000 m.a.s.l.) were overlaid, which divided entire region of Tigray into fifteen agroclimatic zones. Hot semi-arid, warm semi-arid, tepid semi-arid and hot arid were the dominant zones in the region.