K.N. Singh

Conjunctive use of saline and non-saline irrigation waters in semi-arid regions

In arid and semi-arid regions, effluent from sub-surface drainage systems is often saline and during the dry season its disposal poses an environmental problem. A field experiment was conducted from 1989 to 1992 using saline drainage water (EC=10.5–15.0 dS/m) together with fresh canal water (EC=0.4 dS/m) for irrigation during the dry winter season. The aim was to find if crop production would still be feasible and soil salinity would not be increased unacceptably by this practice. The experimental crops were a winter crop, wheat, and pearl-millet and sorghum, the rainy season crops, grown on a sandy loam soil. All crops were given a pre-plant irrigation with fresh canal water. Subsequently, the wheat crop was irrigated four times with different sequences of saline drainage water and canal water. The rainy season crops received no further irrigation as they were rainfed. Taking the wheat yield obtained with fresh canal water as the potential value (100%), the mean relative yield of wheat irrigated with only saline drainage water was 74%. Substitution of canal water at first post-plant irrigation and applying thereafter only saline drainage water, increased the yield to 84%. Cyclic irrigations with canal and drainage water in different treatments resulted in yields of 88% to 94% of the potential. Pearl-millet and sorghum yields decreased significantly where 3 or 4 post-plant irrigations were applied with saline drainage water to previous wheat crop, but cyclic irrigations did not cause yield reduction. The high salinity and sodicity of the drainage water increased the soil salinity and sodicity in the soil profile during the winter season, but these hazards were eliminated by the sub-surface drainage system during the ensuing monsoon periods. The results obtained provide a promising option for the use of poor quality drainage water in conjunction with fresh canal water without undue yield reduction and soil degradation. This will save the scarce canal water, reduce the drainage water disposal needs and associated environmental problems.

Irrigation of wheat with saline drainage water on a sandy loam soil

Abstract Drainage projects to control waterlogging and soil salinity usually face an acute problem of disposal of subsurface saline drainage water out of the project area. A field experiment was, therefore, conducted for 3 years on a sandy loam soil to evaluate the effects of irrigation with drainage water of different salinity levels ( ec iw = 6, 9, 12 and 18–27 dS/m) on soil salinity build-up, growth and yield of wheat (Triticum aestivum). Drainage water ( ec = 18–27 dS / m ) was diluted with canal water ( ec = dS / m ) to obtain ec values of 6, 9 and 12 dS/m. Canal water was used for pre-sowing irrigation and subsequently saline drainage water of different salinity levels was used. Irrigation with diluted drainage water of varying salinity levels in the second and third year decreased the growth and yield significantly, whereas in the first year winter rains (102 mm), during the early growth period, seemed to have nullified the treatment effects. On average, use of 6, 9, 12 and 18–27 dS/m salinity water for 3 years resulted in 4.4, 9.2, 15.9 and 21.3% reduction in grain yield, respectively, as compared to yields with canal water irrigation. Grain protein content was not inferior even when saline drainage water was used without dilution. No problems of soil degradation were observed. Most of the salts accumulated in the preceding crop season were leached out to safe levels by monsoon rains before the next wheat season.

Effect of irrigation scheduling on growth, yield and evapotranspiration of wheat in sodic soils

Abstract To evaluate the critical growth stage for irrigation scheduling of wheat ( Triticum aestivum L.), a field experiment was conducted at Karnal, India during the winter season of 1986–87 and 1987–88 in a sodic soil with pH 9.2, and exchangeable sodium percent ( esp ) 38. An increase in the irrigation frequency resulted in greater relative growth rate, rooting density, productive tiller per meter and grain yield of wheat. The three irrigations given at crown root initiation, tillering and milk stage gave significantly higher grain yield as compared to other treatment with three irrigations. The evapotranspiration ( et ) of the crop increased as the crop season advanced and reached its peak from 60 to 90 days after sowing ( das ). Maximum water use efficiency ( wue ) was recorded when three irrigations were given at crown root initiation, tillering and milk stage rather than at other growth stages. Most of the et occurred from the 0–15 cm soil layer and increased from lower layers (15–30, 30–60, and 60–90 cm soil depth) with an increase in the irrigation frequency, however the total amount of et from all the layers was always greater under higher irrigation frequency.

Effect of irrigation on growth, yield and evapotranspiration of mustard (Brassica juncea) in partially reclaimed sodic soils

Abstract A field experiment was conducted to study the effect of irrigation scheduling of mustard ( Brassica juncea L.) at Karnal, India, during 1987–1988 and 1988–1989 in partially reclaimed sodic soil with pH 8.8 and exchangeable sodium percent (ESP) 23. One irrigation at rosette stage (28–30 days after sowing) gave significantly greater relative growth rate (RGR), branches and pods/plant, seed and straw yields as compared to one irrigation at pod formation stage and unirrigated treatments. Most of the evapotranspiration (ET) of crop occurred from the 0–15 cm soil layer. The total amount of ET of crop from all the layers was always greatest under higher irrigation frequency. Maximum water use efficiency (WUE) was recorded when one irrigation was given at rosette as compared with other treatments. The ET of crop increased as the crop season advanced and reached its peak from 30–60 days after sowing (DAS).

An Empirical Investigation of Arima and Garch Models in Agricultural Price Forecasting

The present study deals with time series models which are non-structural-mechanical in nature. The Box Jenkins Autoregressive integrated moving average (ARIMA) and Generalized autoregressive conditional heteroscedastic (GARCH) models are studied and applied for modeling and forecasting of spot prices of Gram at Delhi market. Augmented Dickey Fuller (ADF) test is used for testing the stationarity of the series. ARCH-LM test is used for testing the volatility. It is found that ARIMA model cannot capture the volatility present in the data set whereas GARCH model has successfully captured the volatility. Root Mean square error (RMSE), Mean absolute error (MAE) and Mean absolute prediction error (MAPE) were computed. The GARCH (1,1) was found to be a better model in forecasting spot price of Gram. The values for RMSE, MAE and MAPE obtained were smaller than those in ARIMA (0,1,1) model. The AIC and SIC values from GARCH model were smaller than that from ARIMA model. Therefore, it shows that GARCH is a better model than ARIMA for estimating daily price of Gram.