In transplanted flooded rice (Oryza sativa L.) culture in Asia, N fertilizer recovery efficiency (RE) estimates are usually greater with the difference method than with the 15N method. These reported differences are greater and more common for transplanted irrigated rice than for upland crops and might be associated with basal N applications when plant demand is low. Added N interactions (ANI), or greater soil N accumulation in fertilized plants than in unfertilized plants, are often cited as the reason for these differences. The causes of ANI can be stimulation of mineralization of soil organic matter by fertilizer or greater root exploration in fertilized plants. The objectives of this pot study were (i) to compare the 15N dilution method using enriched 15N‐urea (5.0 atom %), and 14N‐urea (0.366 atom %) plus 15N‐labeled (0.447 atom %, Maahas clay [isohyperthermic Andaqueptic Haplaquoll]) soil, with the difference method of measuring RE of N, as affected by timing of application, and (ii) to use 15N‐labeled (0.447 atom %) soil to directly measure ANI as 15N accumulation in 14N fertilized pots minus 15N accumulation in unfertilized pots. Recovery efficiency measures at physiological maturity were higher with the difference method (54%) than with the two isotope dilution methods (44%), which were in turn similar. The real ANI measured was negligible, as the root biomass in this clay soil was not greatly affected by fertilization. Therefore, the ANI was apparent and due to isotope substitution. The RE estimate by difference (54.4%) was therefore more accurate than the RE measure by 15N methods (44.4%). The 33.2% of added 15N not accounted for in the plant–soil system was a measure of N fertilizer losses (NH3 volatilization from floodwater, denitrification, NH3 loss through the plant during grain fill) that were not affected by isotope substitution. Recovery efficiency estimated with 15N‐enriched soil plus ordinary urea was identical to the RE estimate using enriched 15N‐urea, although both were underestimations because of isotope substitution.

The Guatemala's rural population have limited resources, high vulnerability to climate change, traditional agriculture practices and adversely affected by water scarcity. These problems engender the need for further economic development and imposed pressure on the existing water resources. In response, Rain Water Harvest (RWH) is the measure as an alternative source towards water shortage problem and a decrease in groundwater extraction. However, the identification of optimal sites for RWH is an important step to maximize the amount of water harvested and minimize the ecological impact. In this study, an Analytical Hierarchy Process (AHP) was used to determinate optimal sites using Geographic Information Systems (GIS) in order to integrate spatial information. Physical and socioeconomic features were main decision criteria along with six sub-criteria: potential runoff; land use; soil texture; slope; distance from agricultural land; and distance from roads. In the investigation, several different criteria with different AHP structures were utilized to assess the flexibility of structures. The result maps with respect to different criteria and AHP structurs are overlaid in a systematic scheme to identify the most suitable site for RWH project. The results identified four sites as optimally suitable and eight as highly suitable. The total 424,070.81 m 3 volume of water can be potentially harvested from these optimally and highly suitable sites. The study

This study devised a practical solution to mitigate urban inundation and artificial recharge of groundwater using recharge wells which is the most viable surface runoff rainwater harvesting (RWH) technique in urban areas. The Rainwater Harvesting Pilot Project at Gaddafi Stadium Lahore was established to deal with urban flooding, artificial recharge of groundwater, and to avoid the mixing of rainwater in municipal sewerage. The study showed that Lahore city has great RWH potential from critical ponding roads that can be utilized to recharge the Lahore aquifer. With that ratio of recharge, the groundwater level can rise to 3.54 ft after every monsoon period if the same recharge wells structure are used, which is a key to groundwater sustainability in Lahore city. Moreover, the maximum recharging capacity of wells was 29.32 m 3 /h with satisfactory performance. Both recharge wells cleared the ponding volume within 3 to 3.5 h after the rainfall stopped. The filter media performance was also favorable with 25%-30% removal of contamination. All the water quality parameters were within the permissible limit against prescribed standards except coliform count that indicated the presence of sewage. In such a case the mixing of charcoal is recommended to shut up the coliform signals. This study identified that RWH using recharge wells is an alternative freshwater supply source for sustainable development of Lahore city and this technique should be the part of Master Planning and Policy Decision of Lahore as a suggestion.Processes 2019, 7, 623 2 of 23 abstraction to fulfil the requirement of the domestic, industrial, and agriculture sectors in Pakistan from last few decades on account of its ubiquitous occurrence, easy availability, and reliability [3]. These qualities have led to its indiscriminate exploitation in dense urban areas of the country such as Lahore without due regard to recharging options. The reckless use of groundwater further aggregates the water scarcity problems, which is a major concern for long term sustainability. To date, more attention has been given to centralized approaches (finding alternative or additional water resources) as compared to decentralized approaches (optimizing water management systems) by water managers and policymakers for fulfilment of sustainable management of freshwater in urban areas. There is an urgent need for development and implementation of water resources management through decentralized approaches such as rainwater harvesting and utilization using artificial recharge structure. This engineering solution for freshwater problems has been proven as a viable option for augmentation of groundwater resources [4][5][6][7].This study mainly focuses on Lahore city, the second-largest urban hub of Pakistan. The city area is facing two severe problems, one is the rapid decline in groundwater level due to extensive extraction of groundwater and the other is regular flooding in the city area during monsoon season. Its expansion over time is owed to several vectors of growth, for exam...

Grafting is a substitute technique to boost tolerance against abiotic stresses, which also diminish root syndromes from soil-borne pathogens and increase crop production. This piloted study evaluates the tongue grafting technique and investigates the influence of grafting hybrid cucumber (Kalam F1) scion onto local cucurbitaceous and hybrid rootstocks on plant morphology, fruit yield, nutrients concentration in different plant organs, and postharvest fruit quality during three seasons of 2017 to 2019, consecutively. The research design was completely randomized (CRD), and the effects of grafted rootstocks were determined with comparison of percent plant survival, growth characteristics, fruit yield, and texture properties (during storage). The experimental results indicated that all rootstocks presented compatibility with hybrid cucumber (Kalam F1) scion and showed significant comparable performance with hybrid rootstock during all seasons in terms of vegetative growth, yield, and storage except pumpkin (68% during the 1st, 74% during the 2nd, and 71% during the 3rd seasons). The plants with Bottle gourd (Lagrenaria siceraria) rootstock showed the highest survival rate as compared to all other cucurbitaceous and hybrid rootstocks during three seasons: 94%, 98%, and 93%, respectively. Similarly, the other factors such as plant height (613, 622, and 615 cm), fruit weight (282, 281, and 277 g), fruit shape index (7.77, 8.18, and 8.25), Total soluble solids (TSS) (5.1%, 5.17%, and 4.96%), fruit dry matter (4.55%, 4.625, and 4.57%), fruit yield (4.37, 4.9, and 3.95 kg/plant), and disease resistance index (<3) during three seasons were comparable with all other cucurbitaceous and hybrid rootstocks. The lower survival rate of pumpkin rootstock made a significant poor performance with lower growth, yield, nutrients, and storage than all other cucurbitaceous rootstocks. Ridge and Bitter gourds showed improved results for vegetative growth, yield, fruit characteristics, nutritional values, and storage performance than that of hybrid cucumber rootstock. The fruit textural and physical properties were found significantly better at 10 °C than 25 °C for 10 days of storage without quality deterioration, while no impact was perceived on physical properties of the fruit. According to economic analysis, the grafted cucumber production system showed higher net return and benefit-cost ratio (BCR) in comparison with the real rooted hybrid cucumber production system, which was assumed to be profitable practice.

This study evaluates the spatiotemporal rainfall variability over the semimountainous Soan River Basin (SRB) of sub-Himalayan Pothwar region, Pakistan. The temporal rainfall trend analysis of sixteen rain gauges was performed on annual basis with long-term (1981–2016) data. The results depicted that there is substantial year-to-year and season-to-season variability in rainfall patterns, and rainfall patterns are generally erratic in nature. The results highlight that most of the highland rainfall stations showed decreasing trends on annual basis. The central and lowland stations of the study area recorded an increasing trend of rainfall except for Talagang station. The average annual rainfall of the study area ranges between 492 mm and 1710 mm in lowland and high-altitude areas, respectively. Of the whole year’s rainfall, about 70 to 75% fall during the monsoon season. The rainfall spatial distribution maps obtained using the inverse distance weighting (IDW) method, through the GIS software, revealed the major rainfall range within the study area. There is a lack of water during postmonsoon months (November–February) and great differences in rainfall amounts between the mountainous areas and the lowlands. There is a need for the rational management of mountainous areas using mini and check dams to increase water production and stream regulation for lowland areas water availability. The spatiotemporal rainfall variability is crucial for better water resource management schemes in the study area of Pothwar region, Pakistan.

This research was undertaken for the evaluation of soil erosion using the semi-distributed basin scale SWAT model for four subcatchments of the Dhrabi River Catchment (DRC), which is located in the Pothwar Plateau region. Two subcatchments (catchment-25 and -31) are characterized by gullies while the other two (catchment-27 and -32) are managed with terraced landuse system. The performance of the model was satisfactory with coefficient of determination (R 2 ) = 0.67 to 0.91 and Nash-Sutcliffe efficiency (E NS ) = 0.54 to 0.85 for both surface runoff and sediment yield during the calibration (2009)(2010) and validation (2011) periods. The P USLE factor was found to be the most sensitive parameter during model calibration.It was observed that all of the rainfall-runoff events occurred during the monsoon season (June to September). The estimated annual sediment loss ranged from 2.6 t/hm 2 to 31.1 t/hm 2 over the duration of the simulation period for the non-terraced catchments, in response to annual precipitation amounts that were between 194.8 mm to 579.3 mm. In contrast, the predicted annual sediment levels for the terraced catchments ranged from 0.52 t/hm 2 to 10.10 t/hm 2 due to similar precipitation amounts. The terraced catchments resulted in 4 to 5 times lower sediment yield as compared to non-terraced catchments. The results suggest that there is a huge potential for terraces to reduce soil erosion in the DRC specifically and Pothwar area generally, which have proven to be an efficient approach to establishing soil and water conservation structures in this region.

Low N fertilizer recovery efficiency (RE) remains a problem in rice (Oryza sativa L.) production in Asia. The chlorophyll meter has been shown to identify when rice is in need of a N top‐dressing, that if applied would result in greater agronomic efficiency (AE) of N fertilizer than commonly practiced, pre‐set timing schemes. Critical chlorophyll meter readings have been used to match N top‐dressing with plant demand for the cultivar IR72, but fixed critical readings may not apply to multiple cultivars and locations. Our objective was to test the approach of using sufficiency indices, calculated from chlorophyll meter readings relative to well‐fertilized reference plots, with several rice cultivars in the Philippines and in India by comparing with local fixed N timing recommendations. Chlorophyll meter readings were significantly affected by N management practice, cultivar, and time of application at both locations. Similar rice yields were produced with chlorophyll meter sufficiency indices compared with the fixed N timing treatment with 30 kg less N ha−1 in the wet season in all cultivars at both locations. Compared with fixed‐timing, 45 kg less N ha−1 was used with the chlorophyll meter in the Philippines dry season without a yield reduction in three of four cultivars. In conclusion, chlorophyll meter sufficiency indices identified when several rice cultivars at two locations needed a N top‐dressing, which resulted in greater AE of N fertilizer than local, pre‐set splits.

Landuse/landcover change (LULCC) and climate change (CC) impacts on streamflow in high elevated catchments are very important for sustainable management of water resources and ecological developments. In this research, a statistical technique was used in combination with the Soil and Water Assessment Tool (SWAT) to the Upstream Area of the Yangtze River (UAYR). Different performance criteria (e.g., R 2 , NSE, and PBIAS) were used to evaluate the acceptability of the model simulation results. The model provided satisfactory results for monthly simulations in the calibration (R 2 ; 0.80, NSE; 0.78 and PBIAS; 22.3%) and the validation period (R 2 ; 0.89, NSE; 0.75 and PBIAS; 19.1%). Major landuse/landcover transformations from 1990 to 2005 have occurred from low grassland to medium grassland (2%) and wetlands (0.9%), bare land to medium grassland (0.2%), glaciers to wetland (16.8%), and high grassland to medium grassland (5.8%). The results show that there is an increase in average annual runoff at the Zhimenda station in UAYR by 15 mm of, which approximately 98% is caused by climate change and only 2% by landuse/landcover change. The changes evapotranspiration are larger due to climate change as compared to landuse/landcover change, particularly from August to October. Precipitation and temperature have increased during these months. On the contrary, there has been a decrease in evapotranspiration and runoff from October to March which depicts the intra-annual variations in the vegetation in the study area. KeywordsClimate change • Land cover • Land use change • Mann Kendall • Qinghai Tibet • SWAT model • Yangtze River