Muhammad Amjad Bashir

Potassium (K) and zinc (Zn) are mineral nutrients required for adequate plant growth,
enzyme activation, water retention and photosynthetic activities. However, Pakistani soils are alkaline and have serious problems regarding Zn deficiency. The current study aims at finding the nutrient–nutrient interaction of K and Zn to affect maize plants’ (i) physiological processes and (ii) productivity. For this purpose, a pot experiment was conducted at the research area of the
Department of Soil Science, Faculty of Agricultural Science and Technology, Bahauddin Zakariya University, Multan. Two maize genotypes, DK-6142 (hybrid) and Neelam (non-hybrid), were used with three K fertilizer doses, i.e., 0, 60 and 100 kg ha−1 in all possible combinations with three
Zn fertilizer doses, i.e., 0, 16 and 24 kg ha−1. The treatments were replicated under a completely randomized block design. The results elucidated that the combined application of K and Zn with K60 + Zn16 treatment significantly increased agronomic, productive, and physiological attributes. It has improved fresh biomass (89%), dry biomass (94%), membrane stability index (142%), relative water content (200%) and chlorophyll contents (191%) as compared to the control. Moreover, the mineral uptake of K and Zn was significantly improved with their maximum fertilization rate in
hybrid genotype compared to non-hybrid and CK.

Sugar industry produces a variety of organic byproducts causing disposal as well as environmental issues. This study investigated the safe use of these byproducts in assessment of soil physicochemical properties and metal accumulation in rice.

Adopting agroforestry practices in many developing countries is essential to combat climate change and diversify farm incomes. This study investigated the above and below-ground biomass and soil carbon of a citrus-based intercropping system in six sites (subdivisions: Bhalwal, Kot Momin, Sahiwal, Sargodha, Shahpur and Silanwali) of District Sargodha, Southeast Pakistan. Tree biomass production and carbon were assessed by allometric equations through a non-destructive approach whereas, soil carbon was estimated at 0–15 cm and 15–30 cm depths. Above and below-ground biomass differed significantly, and the maximum mean values (16.61 Mg ha−1 & 4.82 Mg ha−1) were computed in Shahpur due to greater tree basal diameter. Tree carbon stock fluctuated from 6.98 Mg C ha−1 to 10.28 Mg C ha−1 among selected study sites. The surface soil (0–15 cm) had greater bulk density, organic carbon, and soil carbon stock than the subsoil (15–30 cm) in the whole study area. The total carbon stock of the ecosystem ranged from 25.07 Mg C ha−1 to 34.50 Mg C ha−1 across all study sites, respectively. The above findings enable us to better understand and predict the carbon storage potential of fruit-based agroforestry systems like citrus. Moreover, measuring carbon with simple techniques can produce trustworthy outcomes that enhance the participation of underdeveloped nations in several payment initiatives such as REDD+

Integrated pest management adoption is quite low around the globe, particularly in developing countries, due to different factors. Here, we examine the factors affecting the intention of Pakistani farmers to adopt integrated pest management practices in vegetable production using a structured questionnaire. We interviewed 301 vegetable growers in Multan, Pakistan. The reliability and validity of the data, along with the underlying relationship between the observed variables, were identified through exploratory factor analysis. The majority of the farmers (79.4%) relied on pesticides for pest control. More than four out of 10 of the respondents (43.8%) reported that okra received the highest application of pesticides followed by potato (24.5%) and cauliflower (17.9%). Integrated pest management was currently nonexistent among the vegetable growers of the study area. The latent factors—“knowledge of the adverse effects of pesticide,” “belief in the efficacy of non-chemical pest control measures,” “perceived barriers to the adoption of integrated pest management,” “progressive farming approach,” and “intention to adopt integrated pest management”—were subsequently confirmed using confirmatory factor analysis. The structural equation model suggested that the intention to adopt integrated pest management is significantly affected by farmers’ knowledge of the adverse effects of pesticides (b = 0.274, z-value = 3.082, P = 0.002). An increase in farmers’ awareness of the harmful effects of pesticides could lead to integrated pest management adoption for pest control. The scale for intention to adopt integrated pest management developed in this study can be used in future studies and provide valuable insights to the policymakers for devising integrated pest management adoption campaigns in the study area.

Anthropogenic activities such as mining, manufacturing, and application of fertilizers release substantial quantities of cadmium (Cd) into the environment. In the natural environment, varying pH may play an important role in the absorption and accumulation of Cd in plants, which can cause toxicity and increase the risk to humans. We conducted a hydroponic experiment to examine the impact of pH on cadmium (Cd) solubility and bioavailability in winter wheat (Triticum aestivum L.) under controlled environmental conditions. The results showed that Cd concentration was significantly reduced in wheat with an increase in pH from 5 to 7, while it was dramatically increased at pH ranging from 7 to 9. However, in both cases, a significant reduction in physiological traits was observed. The addition of Cd (20, 50, and 200 μmol L-1) at all pH levels caused a substantial decline in wheat growth, chlorophyll and carotenoids contents, nutrient availability, while elevated cell membrane damage was observed in terms of electrolytic leakage (EL), osmoprotectants, and antioxidants activity. In our findings, the negative effects of acidic pH (5) on wheat growth and development were more pronounced in the presence of Cd toxicities. For instance, Cd concentration with 20, 50, and 200 μmol L-1 at acidic pH (5) reduced shoot dry biomass by 45%, 53%, and 79%, total chlorophyll contents by 26%, 41%, 56% while increased CAT activity in shoot by 109%, 175%, and 221%, SOD activity in shoot by 122%, 135%, and 167%, POD activity in shoot by 137%, 250%, and 265%, MDA contents in shoot by 51%, 83%, and 150%, H 2 O 2 contents in shoot by 175%, 219%, and 292%, EL in shoot by 108%, 165%, and 230%, proline contents in shoot by 235%, 280%, and 393%, respectively as compared to neutral pH without Cd toxicities. On the other hand, neutral pH with Cd toxicities alleviated the negative

The traditional co-culture systems have attained the attention for better production, still have gaps to identify key factors influencing the safe grain production, yield enhancement, and economic viability. Here, a field survey and a field experiment was conducted in Panjin city, including two production systems: rice-monoculture (RM) and RC system. The treatments of field experiments were: rice-monoculture (RM), 3000 crabs ha − 1 without feed (RC3000), 6000 crabs ha − 1 with feed (RC6000), and 12000 crabs ha − 1 with 2 × feed (RC12000). During field survey, higher number of crabs reduced the number of productive tillers while, the productive traits were improved significantly except 1000-grain weight was insignificant. Field experiment indicated that suitable stocking density and feed management has no negative effect on agronomic or productive trait. Grain yield was improved (19.9%) in RC3000, (22.0%) in RC6000, and (14.7%) in RC12000 as compared to RM. The reduction in shrivelled grains spike − 1 , and the increase in filled grains spike − 1 , seed setting percentage, and 1000-grain weight in RC system improved the rice production. Grain nitrogen, phosphorus, and potassium contents were also improved by RC6000. Farm income and benefit-cost ratio were higher in RC system, meanwhile, the maximum farm production (16231-yuan ha − 1) and benefit-cost ratio (0.51) were in RC6000. The RC system can control drained out water nutrients concentrations, which helps in water pollution control. The results suggested that RC system improves the clean grain and farm production, resource utilization, and the economic status with managed optimum stocking density and feed.

Rice-crab co-culture (RC) is an environmentally friendly, agri-aquaculture technique, however, its knowledge about soil nutrients status and their composition in rice grain has remained unexplored. The aim of current study is to explore this deficiency. Thus, a field survey and a field experiment were combinedly carried out at Panjin City, China. The field survey with 16 fields each for rice-monoculture (RM) and RC was conducted without influencing conventional cultural practices. The field experiment was conducted with four treatments: rice-monoculture (RM), 3000 crabs ha
1 without feed (RC3000), 6000 crabs ha
1 with feed (RC6000), and 12,000 crabs ha
1 with 2  feed (RC12000). Results showed an increase in soil nutrients and improved nutrient accumulation in rice with the RC system. Soil organic carbon, macronutrients (nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg)), microbial biomass carbon, and nitrogen, micronutrients (copper, zinc (Zn), and manganese) were improved. From the field survey, results indicated significant improvement in grain TN (9.4%), calcium (Ca, 22.1%), Mg (7.1%), and Zn (26.1%) in RC system compared to RM system. In field experiment, the concentrations of Ca, Mg, and Zn were increased as follows: i) Grain Ca in RC3000 (23.9%) and RC6000 (17.1%), ii) Mg in RC3000 (12.6%), RC6000 (16.3%), and RC12000 (11.8%), iii) Zn in RC3000 (10.8%), RC6000 (5.7%), and in RC12000 (14.8%). The RC system has also improved nutrients translocation from soil to plant biomass that was the key reason to increase nutrient composition in rice. The results implied that the improvement of rice yield was by the increased nutrient in soil and the higher nutrient translocation capacity from soil to rice under the proper culturing crab density.

The curve number (CN) method developed by the United States Department of Agriculture (USDA) in 1954 is the most common adopted method to estimate surface runoff. For years, applicability of the CN method is a conundrum when implementing to other countries. Specifically, countries with more complex natural environment may require more dedicated adjustments. Therefore, the current CN lookup table provided by USDA might not be appropriate and could be questionable to be applied directly to
regions elsewhere. Some studies have been conducted to modify CN values according to specified natural characteristics in scattered regions of mainland China. However, an integral and representative work is still not available to address potential concerns in general matters. In this study, a large set of rainfall runoff monitoring data were collected to adjust CN values in 55 study sites across China. The results showed that the revised CN values are largely different from CN look-up table provided by USDA, which would lead to huge errors in runoff estimation. In this study, the revised CN (dubbed CN-China) provides better reference guidelines that are suitable for most natural conditions in China. In addition, scientists and engineers from other parts of the world can take advantage of the proposed work to enhance the quality of future programs related to surface runoff estimation

Rice (Oryza sativa L.) is a staple food for three billion people and paddy fields contribute greatly to greenhouse gases (GHG) emission and environmental nitrogen losses. Rice paddies need to be managed in a novel and sustainable way to promote production. Here, we critically review the potential benefits and constrains of a novel rice production system, the co-culture of rice and aquatic animals. The review helps to answer important questions: how would the co-culture affect farm profitability, water quality, and GHG emission? What are the major benefits and constraints for adopting the co-culture system? The review revealed that rice-animal co-culture provided ecological, economic, and social benefits such as increasing farm productivity and greater resource utilization efficiencies, and that the system could increase biodiversity, improve water and soil quality, and reduce GHG emissions. However, despite its potential benefits, the adoption of the system has been constrained by the lack of science-based extension programs and the farmers' concerns over drought-related production risks. Moreover, misusing the system by adopting unpractically high culture density (high animal feed input) and/or in undesirable field conditions may lead to deteriorating water quality and lowering farm profitability. The review suggests that more research is needed to evaluate the impacts of the rice-animal co-culture system under variable climate and field conditions and to identify factors controlling their negative impacts. Furthermore, a strong extension program, with policy and technological guidance from the government and non-governmental organizations, is needed to achieve the wide adoption of the co-culture practice.

A B S T R A C T Nitrogen (N) leaching is an important factor that threatens groundwater safety in intensive greenhouse vegetable production regions. However, managing irrigation and fertilization to reduce nitrate leaching has rarely been carried out in long-term experiments. In this study, N leaching in two typical greenhouse vegetable systems (a cucumber-cucumber system in Shandong and a cucumber-tomato system in Ningxia) from 2008 to 2013 investigated should be studied using a lysimeter monitoring method. The total N fertilization rate was 0 to 2508 kg N ha −1 which included three treatments: no fertilizer (CK: 0 kg N ha-1), conventional treatment (CON: Shandong 2508 kg N ha-1 and Ningxia 2239 kg N ha-1) and reduced fertilizer application (RF: Shandong 2164 kg N ha-1 and Ningxia 1716 kg N ha-1). The irrigation amount was 590–2919 mm year-1 according to vegetable water demand. The results indicated that the annual total N leaching were 344.8 kg ha −1 (192.3–508.3 kg ha −1) in Shandong and 170.7 kg ha −1 (134.9–203.7 kg ha −1) in Ningxia for the CON treatments. Compared with CON treatment, RF significantly decreased ANLL, while simultaneously maintaining the yield and increasing the downward trend of the annual TN leaching factor (ANLF) year by year. Meanwhile, a concomitant annual cost reductions associated with the RF treatment estimated at $187 million USD for Shandong and $20 million USD for Ningxia. ANLL increased linearly with the N input (p < 0.05). More than half of ANLL came from fertilizer N (including chemical and manure fertilizer) under CON treatments, while more than half of ANLL came from soil and water N under RF treatments. The results indicated that mitigation measures for N leaching pollution from greenhouse vegetable fields should consider regulations on irrigation and fertilization.

Wheat (Triticum aestivum L.) is one of the major cereal crops of the world, which is grown under diverse climatic conditions across the globe. It is consumed as a staple food by the people of Pakistan. However, its productivity is low as compared to the potential of varieties being cultivated. Phosphorus (P) application is very important to increase the yield of wheat. In this study, wheat productivity was evaluated under different P application rates and techniques. It was applied through band-placement, broadcasting and fertigation at seven different levels (viz. 0, 25, 50, 75, 100, 125, 150 kg P 2 O 5 ha –1). The results revealed that P fertigation improved yield parameters, straw and grain P contents, P uptake and protein in wheat grain as compared to other techniques. Moreover, the high Olsen P was found for broadcasting technique. The applied P at higher rates increased the P contents, its uptake, Olsen P and wheat yield; P fertigation at 125 kg P 2 O 5 ha –1 was more appropriate and economically viable for increasing the wheat yield.

The impacts of manure application on soil ammonia (NH3) volatilization and greenhouse gas (GHG) emissions are of interest for both agronomic and environmental reasons. However, how the swine manure addition affects greenhouse gas and N emissions in North China Plain wheat fields is still unknown. A long-term fertilization experiment was carried out on a maize-wheat rotation system in Northern China (Zea mays L-Triticum aestivum L.) from 1990 to 2017. The experiment included four treatments: (1) No fertilizer (CK), (2) single application of chemical fertilizers (NPK), (3) NPK plus 22.5 t/ha swine manure (NPKM), (4) NPK plus 33.7 t/ha swine manure (NPKM+). A short-term fertilization experiment was conducted from 2016 to 2017 using the same treatments in a field that had been abandoned for decades. The emissions of NH3 and GHGs were measured during the wheat season from 2016 to 2017. Results showed that after long-term fertilization the wheat yields for NPKM treatment were 7105 kg/ha, which were higher than NPK (3880 kg/ha) and NPKM+ treatments (5518 kg/ha). The wheat yields were similar after short-term fertilization (6098–6887 kg/ha). The NH3-N emission factors (EFamm) for NPKM and NPKM+ treatments (1.1 and 1.1–1.4%, respectively) were lower than NPK treatment (2.2%) in both the long and short-term fertilization treatments. In the long- and short-term experiments the nitrous oxide (N2O) emission factors (EFnit) for NPKM+ treatment were 4.2% and 3.7%, respectively, which were higher than for the NPK treatment (3.5% and 2.5%, respectively) and the NPKM treatment (3.6% and 2.2%, respectively). In addition, under long and short-term fertilization, the greenhouse gas intensities for the NPKM+ treatment were 33.7 and 27.0 kg CO2-eq/kg yield, respectively, which were higher than for the NPKM treatment (22.8 and 21.1 kg CO2-eq/kg yield, respectively). These results imply that excessive swine manure application does not increase yield but increases GHG emissions.

In this study, anaerobic digestion was carried out along with bentonite addition to avoid ammonia accumulation, which significantly inhibits methane production. To make better use of bentonite, calci-nations were applied for modification. Chicken manure was anaerobically digested for 75 days at 35 ± 1 C in lab-scale sequencing batch reactors. Better performance in methane production and process stability was observed in reactors treated with bentonite, compared to those without bentonite. Among all treatments, the maximum increase of 41% in cumulative methane was found with the treatment where bentonite thermally modified at 300 C was applied. The treatment also revealed stable variation of pH, total ammonia nitrogen (TAN), and free NH 3 contents. In addition, adsorption capacity of bentonite to TAN was enhanced significantly with thermal modification as well, the TAN concentration reduction was improved by 5%e12% compared to natural bentonite.

Phosphorus (P) is the second most important macronutrient and is deficient in most of the agricultural soils based on higher retention with soil and poor recovery from the applied fertilizers. A field experiment was conducted in 2009–2012 in which different organic wastes of agricultural and industrial origin with inorganic P fertilizer to improve crop yield, P use efficiency and physic-chemical properties of soils in salt affected soils under rice–wheat cropping system. The treatments included; P at farmer practice, P on soil need basis, PoM + chemical fertilizer (1:1), MSWC + chemical fertilizer (1:1), PrM + chemical fertilizer (1:1) and FM + chemical fertilizer (1:1). Analysis showed that nutrients source significantly improved vegetative and yield attributes of rice and wheat crops. However, application of PoM + chemical fertilizer on soil need basis significantly improved the growth and yield attributes of both crops and soil physic-chemical properties than all the other treatments. The effectiveness of treatments could be arrange as PoM + chemical fertilizer on soil need basis > FM + chemical fertilizer on soil need basis > MSWC + chemical fertilizer on soil need basis > PrM + chemical fertilizer on soil need basis > P on soil need basis > P at farmer practice, respectively. In conclusion, integration of organic and chemical P fertilizer resulted in well-balanced nutrient management plan. Application of PoM + chemical fertilizer on soil need basis is recommended as an effective and economical integrated nutrient management practice enhancing productivity of rice–wheat crop and improving physical and chemical properties of salt affected soils.

Plant growth stimulators (growth regulators + biostimulants; PGS) are
chemical substances (organic/inorganic), helpful in plant growth and development. These are not considered as the replacement of fertilizers but can help in improved crop and soil quality. Both compounds can amplify the root biomass, nutrients translocation, enzymatic activities, crop yield, physiology, and nutrient uptake. Biostimulants are rich in minerals, vitamins, plant hormones, oligosaccharides, and amino acids. These compounds have a serious role to improve soil health, fertility,
sorption, and desorption of nutrients. Hence, have a vital character in nutrients cycling, abiotic stress control, heavy metals bioavailability, and greenhouse gaseous emission. This chapter focuses on the discussions about the influence of plant growth regulators and biostimulants in crop production, soil health, heavy metal cycling, greenhouse gases emission with environmental sustainability. Whereas, the impact of biostimulants on greenhouse gases is a research gap.