scholarly journals Interactive comment on “Establishing relationship between measured and predicted soil water characteristics using SOILWAT model in three agro-ecological zones of Nigeria” by OrevaOghene Aliku and Suarau O. Oshunsanya

2016 ◽  
Author(s):  
Anonymous
2016 ◽  
Author(s):  
OrevaOghene Aliku ◽  
Suarau O. Oshunsanya

Abstract. Soil available water (SAW) affects soil nutrients availability and consequently affects crop performance. However, field determination of SAW for effective irrigated farming is laborious, time consuming and expensive. Therefore, experiments were initiated at three agro-ecological zones of Nigeria to compare the measured laboratory and predicted soil available water using SOILWAT model for sustainable irrigated farming. One hundred and eighty soil samples were collected from the three agro-ecological zones (Savannah, Derived savannah and rainforest) of Nigeria and analysed for physical and chemical properties. Soil texture and salinity were imputed into SOILWAT model (version 6.1.52) to predict soil physical properties for the three agro-ecological zones of Nigeria. Measured and predicted values of field capacity, permanent wilting point and soil available water were compared using T-test. Predicted soil textural classes by SOILWAT model were similar to the measured laboratory textural classes for savannah, derived savannah and rainforest zones. However, bulk density, maximum water holding capacity, permanent wilting point and soil available water were poorly predicted as significant (p < 0.05) differences existed between measured and predicted values. Therefore, SOILWAT model could be adopted for predicting soil texture for savannah, derived savannah and rainforest zones of Nigeria. However, the model needs to be upgraded in order to accurately predict soil water characteristics of the aforementioned locations for sustainable irrigation planning.


2021 ◽  
Vol 13 (12) ◽  
pp. 6910
Author(s):  
Adil Dilawar ◽  
Baozhang Chen ◽  
Arfan Arshad ◽  
Lifeng Guo ◽  
Muhammad Irfan Ehsan ◽  
...  

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.


2021 ◽  
Vol 31 (5) ◽  
pp. 1452-1464
Author(s):  
Zhong-qun GUO ◽  
Jian-rong ZHOU ◽  
Ke-fan ZHOU ◽  
Jie-fang JIN ◽  
Xiao-jun WANG ◽  
...  

2021 ◽  
Vol 312 ◽  
pp. 107317
Author(s):  
Nirmalendu Basak ◽  
Biswapati Mandal ◽  
Ashim Datta ◽  
Manik Chandra Kundu ◽  
Arvind Kumar Rai ◽  
...  

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