Application of carboxymethyl cellulose sodium (CMCNa) in maize-wheat cropping system (MWCS) in coastal saline-alkali soil

Sodium carboxymethyl cellulose (CMCNa) application has been a promising approach to improve soil quality. The purpose of this study was to explore the effects of CMC-Na on soil infiltration, evaporation, water-salt distribution, crop growth, water use efficiency and net profit (Net) in a coastal saline-alkali soil maize-wheat cropping system (MWCS). Five CMC-Na application amounts (0, 0.1, 0.2, 0.4 and 0.6 g kg-1) were designed for the soil column experiment indoor, and five CMC-Na application amounts were used in 2019-2020 field experiment (CK: 0, C10: 10 kg ha-1, C20: 10 kg ha-1, C30: 10 kg ha-1 and C50: 10 kg ha-1), No treatment will be applied in 2021. The results showed that (1) CMC-Na treatment reduced soil cumulative infiltration, infiltration rate, daily evaporation, and cumulative evaporation. (2) After the application of CMCNa, the average soil water storage (SWS) in the 0-60 cm soil layer increased, and soil salinity (SSC) decreased in most treatments. (3) In the 2019-2020, the maize aboveground biomass (B), yield (Y) and water use efficiency (WUE) were the highest under the C20 and C30 treatments, which were 15.24 and 15.32 t ha-1, 5.67 and 5.49 t ha-1 and 1.74 and 1.52 kg ha-1 mm-1, respectively, and the wheat under C30 treatment is the highest, which were 10.98 t ha-1, 5.27 t ha-1 and 1.78 kg ha-1 mm-1. (4) A dose of 25.5 kg ha-1 and 38.9 kg ha-1 was recommended as the most optimal CMC-Na application for maize and wheat in coastal saline alkali soil, respectively.

Increasing cassava root yield on farmers' fields in Nigeria through appropriate weed management

Weed competition is the major biological stress affecting cassava production in smallholder farms in West and Central Africa, where yields are low compared with those in Asia and Latin America. Options for improved weed management are crucial in increasing productivity. Selected pre- and post-emergence herbicides, integrated with appropriate tillage and plant spacing, were tested in 96 sites in four locations in Nigeria, 24 in 2016 and 72 in 2017. Trials were split plots with six pre-emergence herbicides and no post-emergence treatment as main plots. Subplot treatments were four post-emergence herbicides, weeding with a motorized rotary weeder, short- and long-handled hoes, and no post-emergence weed control, i.e., regardless of pre-emergence treatments. Indaziflam-based treatments, irrespective of post-emergence treatment, and flumioxazin + pyroxasulfone applied pre-emergence followed by one weeding with a long-handled hoe provided >80% control of major broadleaf and grass weeds. Compared with herbicide use, farmer control practices (53%) were not efficient in controlling weeds. The highest root yield was produced where (1) s-metolachlor was combined with atrazine, and one weeding with a long-handled hoe or clethodim with lactofen, and (2) indaziflam + isoxaflutole was combined with glyphosate. An increase in root yield from 3.41 to 14.2 t ha-¹ and from 3.0 to 11.99 t ha-¹ was obtained where herbicides were used compared with farmers' practice and manual hoe weeding. Our results showed that integrating good agronomic practices with safe and effective use of appropriate herbicides can result in root yield >20 t ha^-1. i.e., twice the national average root yield of 8-12 t ha^-1, with >50% net profit. The use of appropriate herbicides can reduce the amount of manual labor required and improve livelihoods, specifically for women and children. Smallholder cassava farmers would require continuous training on the safe use and handling of herbicides to improve efficiency and prevent adverse effects on humans and the environment.

Agronomic and economical characterizations of a two-harvest regime for oat forage in cold regions of Northern China

The natural grasslands in northern China have been seriously degraded due mainly to overgrazing and climate change in recent decades, leading to shortage of forage supply to animal husbandry. To maximize forage production, we developed a two-harvest regime of oat forage by sowing in spring in an alpine region of Hulun Buir, northern China, using two oat early maturation species. The agronomic characteristics and forage quality of the two-harvest regime were evaluated across three constructive years from 2017 to 2019. Compared to the traditional one-harvest regime, the production, resource use efficiency, and economic benefits were compared and quantified for both oat species across the 3 years. Dry weight forage by the two-harvest regime was increased by 17.5-18.5%, while crude protein was increased by 25.1-30.0%. Growing days by the two-harvest regime was increased by 36.7% on average, nitrogen fertilizer use efficiency was enhanced by 25.1-30.0%, while water use efficiency was not significantly changed. The two-harvest regime also increased the net profit by 28.0%. Taken together, our results reveal that the two-harvest regime of forage production in the cold region of northern China is a promising practice with high forage yield, nutritional value, and nitrogen fertilizer use efficiency as well as economic profit.

Assessing rice production sustainability performance indicators and their gaps in twelve sub-Saharan African countries

The benchmarking and monitoring of rice production performance indicators are essential for improving rice production self-sufficiency, increasing profitability, reducing labor requirements, optimizing fertilizer inputs, engaging youths in rice production, and increasing the overall sustainability of smallholder rice production systems in countries in sub-Saharan Africa (SSA). In this paper, we quantified five sustainability performance indicators (grain yield, net profit, labor productivity, and nitrogen (N) and phosphorus (P) use efficiencies) to benchmark rice production systems in SSA. Data were collected between 2013-2014 from 2907 farmers from two rice production systems (irrigated and rainfed lowlands) across five agroecological zones (arid, semiarid, humid, subhumid and highlands) in 12 countries (Benin, Cameroon, Cote d'Ivoire, Ghana, Madagascar, Mali, Niger, Nigeria, Senegal, Sierra Leone, Tanzania and Togo). The exploitable gap for each indicator (the difference between the mean of 10 % highest-yielding farms and the mean-yielding farms) was calculated across the countries, the two production systems and agroecological zones. The mean yield varied widely between 2.5 to 5.6 t ha^-1 and 0.6 to 2.3 t ha^-1 in irrigated and rainfed lowlands, respectively, with an average yield of 4.1 and 1.4 t ha^-1, respectively. Across the country-production system combinations, there were yield gaps of 29-69 %, profit gaps of 10-89 %, and labor productivity gaps reaching 71 %. Yield, profit, and labor productivity were positively correlated. They were also positively correlated with N and P fertilizer application rate, but not with N and P use efficiencies. Only between 34-44 % of farmers had desirable ranges in N- or P-use efficiencies in the two production systems. All sites for rainfed lowlands were characterized by low-yield and large gaps in yield, profit, and labor productivity, whereas irrigated lowlands in some countries (Madagascar, Mali, and Togo) have similar characteristics as rainfed ones. We conclude that there is an urgent need to disseminate precision nutrient management practices for optimizing nutrient use efficiency and enhancing rice performance indicators especially in rainfed lowlands as well as low-yielding irrigated lowlands. Furthermore, we propose recommendations for specific categories (i.e. farmer, rice production system, agroecological zone and country) to close performance indicator gaps and to allow the production at scale to achieve rice self-sufficiency in SSA.

Evaluation of environmental consequences affecting human health in the current and optimal cropping patterns in the eastern Lorestan Province, Iran

Planning for optimal use of resources and reduction of environmental impacts, in addition to resource protection, is associated with increasing farmers' revenues and boosting the regional economy. Given the limited resources and environmental impacts of agricultural activities on human health, it is necessary to determine an appropriate cropping pattern. The present research aimed to maximize net profit and minimize environmental impacts, including the releases of carcinogens, noncarcinogens, ozone layer depletion, ionizing radiation, and respiratory inorganics and organics on human health. In this study, an optimal cropping pattern of irrigated and rainfed crops was proposed for the east of Lorestan Province using multi-objective nonlinear programming (MOP). Results showed that the cropping areas of chickpea, rapeseed, and potatoes decreased by 50% in the irrigated crop of MOP model and that of lentil in the MOP model of rainfed crops compared with the current pattern. Another important result was increases in the cropping areas of lentil and bean in the MOP pattern of irrigated crops and wheat in the rainfed MOP model. The environmental impacts of agricultural sector on human health can be reduced by determining an optimal cropping pattern. The implementation of this model in the region reduced the emissions of carcinogens (4%), noncarcinogens (9%), respiratory inorganics (17%), ionizing radiation (14%), ozone layer depletion (17%), and respiratory organics (15%) compared with the existing situation along with an increased net profit of $968,483. According to the findings, consideration of environmental objectives affecting human health is essential in the optimization of the cropping pattern. In addition to optimal use of water and land resources, using the proposed model helps to increase profits and reduce environmental consequences on human health.

Integrated systematic approach increase greenhouse tomato yield and reduce environmental losses

High input - high output greenhouse vegetable systems are responsible for nutrient surpluses and environmental losses. Integrated strategies that improve soil, crop and nutrient management are needed to ensure more sustainable production systems. We conducted a two-year field experiment to evaluate the potential of integrated soil-crop system management (ISSM) practices to improve the productivity and environmental outcomes from an intensive greenhouse tomato production system in the Yangtze River Basin, China. Four treatments were tested: i) farmers' practice (FP); ii) soil remediation (SR), where lime nitrogen with compost addition was the only management strategy; iii) a treatment that combined soil remediation with optimized crop planting density (SRCO), which increased planting density for improving crop yield; and iv) integrated soil-crop system management (ISSM), as a systematic integrated approach, which included the combined optimization of soil remediation, crop optimization, and nutrient management. In the integrated soil-crop system management treatment, nutrient management was optimized through adoption of the most appropriate type (formula) of fertilizer for the crop, rate and application timing of synthetic fertilizer, and by substituting poultry manure with compost. Our results indicated that the fruit yield of the integrated soil-crop system management treatment was 104 t ha^-1, 13.4%-37.3% higher than that of the other three treatments. The mean reactive nitrogen loss (81.1 kg N ha^-1) and the greenhouse gas emissions (6495 kg CO₂-eq ha^-1) in the farmers' practice treatment were much higher than in the other three treatments (reactive nitrogen loss: 47.9-54.3 kg N ha^-1; and greenhouse gas emissions: 4926-5468 kg CO₂-eq ha^-1, respectively). The mean nitrogen and carbon footprints of the integrated soil-crop system management treatment were significantly lower than those of other treatments, as a result of both the lower fertilizer nitrogen use and the greater yield. This study indicates that integrated soil-crop system management could produce greater yields and increase net profit with reduced nitrogen inputs, whilst reducing the environmental cost associated with conventional farmers' practice in plastic-greenhouse vegetable production systems.

Measuring the net profit of laboratory services: A case study in Iran

Background: Clinical laboratories need to manage resources properly and scientifically to survive in today's highly competitive environment. In this context, scientific-economic principles should be considered to determine the profitability or loss of laboratories. Thus, in this study, the net profit of laboratory services was measured based on scientific-economic principles.

Methods: This was an applied research with descriptive-retrospective approach. A laboratory was selected from 61 laboratories of Kerman, Iran, which performed the highest number of tests among the laboratories of this city. In addition, due to easy access, it was the most visited laboratory by patients. The present study had 2 main phases: (1) measuring the price of services and (2) calculating the net profit of the studied laboratory. Data analysis was performed using activity- based costing (ABC) as an econometric model and Excel software.

Results: The highest charges were related to direct costs (78.28%); consumable goods (47.26%) and professional and logistic human resources (46.31%) had the highest share of these costs. In the test groups, the most expensive tests belonged to the hormones (23.03%) and clinical chemistry (20.84%). Total cost, revenue, and the net profit of the studied laboratory were 641 645, 1 390 942, and 749 297 USD, respectively. After doing sensitivity analysis (50% increase in the frequency of tests), the following values were obtained: 987 071, 2 086 413, and 1 099 342, respectively.

Conclusion: Some test groups in the studied laboratory were not profitable, and this was due to the high cost of these tests and illogical tariffs. One way to overcome this problem is to increase the frequency of laboratory tests.