Partial Factor Productivity, Agronomic Efficiency, and Economic Analyses of Maize in Wheat-Maize Cropping System in Pakistan

Getting maximum benefits from cereals do not lie in reducing N-rate and its number of splits but lowering cost per unit cereal production through higher yields. Field experiments were conducted on maize (Zea mays L.) at the New Developmental research Farm of NWFP (Northwest Frontier Province) Agricultural University Peshawar-Pakistan during 2002-03 and 2003-04 in order to investigate effects of variable rates of N and its time of application on the partial factor productivity (PFPN), agronomic efficiency (AEN), net returns (NR), value-cost ratio (VCR) and marginal returns (MR). The 2 x 3 x 6 factorial experiment was designed having two plant densities (D1 = 60,000 and D2 = 100,000 plants ha-1) and three N levels (N1 = 60, N2 = 120 and N3 = 180 kg N ha-1) applied to main plots, while six split application of N in different proportions were applied to subplots in two equal (T1), three equal (T2), three unequal (T3), four equal (T4), five equal (T5) and five unequal splits (T6) at sowing and with 1st, 2nd, 3rd and 4th irrigation at two wk intervals. Maize ranked first with maximum PFPN, AEN, NR, VCR and MR at higher than at lower plant density, and the increase in all these parameters studied in the experiments was more in 2003-04 as compared to 2002-03. Both PFPN and AEN showed negative relationship with increase in N rates and the cast that vary, but NR, VCR and MR showed positive relationship with increase in N rates and the cost that vary. Among time of N application, maximum PFPN, AEN, NR, VCR and MR were calculated when N was applied in five equal splits (T5) almost comparable with T4 and T6 but was more economical when compared with T1, T2, and T3. In conclusion, the findings suggest that growing maize at D2 applied with N3 in four to five splits is more economical in the wheat-maize cropping system of NWFP.maize, Zea mays L., planting density, nitrogen, agronomic efficiency, economics, Crop Production/Industries, Farm Management, International Development, Production Economics, Productivity Analysis,

Nitrogen and harvest impact on warm-season grass biomass yield and feedstock quality

Perennial warm-season grasses including switchgrass (Panicum virgatum L.), big bluestem (Andropogon geradii Vitman), and Indiangrass (Sorghastrum nutans L.) have drawn interest as bioenergy feedstocks due to their high yielding capacity with minimal amounts of inputs under a wide range of environments, and their capability to produce multiple environmental benefits. Nitrogen (N) fertility and harvest timing are considered as critical management practices when optimizing biomass yield and the feedstock quality of these grasses. The objective of this investigation was to quantify the impact of N fertilizer rate, N timing and harvest date on warm season biomass dry matter yield. Research was conducted in 2014 and 2015 on a total of four field-plot locations situated in central and west-central Missouri. Nitrogen fertilizer was applied using dry ammonium nitrate at the rates of 0, 34, 67, and 101 kg ha-1 at two application times, all N early spring and split N (early spring and following 1st harvest). Harvest treatments were as follows: 1) one cut in September; 2) one cut in November; 3) one cut in June and a second in September; and 4) one cut in June and a second in November. Treatments were arranged in a split-plot design with N rate as the main plot and harvest as the sub-plot in arandomized complete block design. Both N and harvest date and their interactions impacted biomass yield at all four locations. Delaying harvesting until late fall or killing frost increased yield. November harvest in combination with N rates grater than or equal to 67 kg ha-1 year-1 produced higher yields compared to the control and 34 kg ha-1N treatments and other harvest timing strategies. Although N was needed to optimize yield, partial factor 24 productivity (PFP) of applied N was flat when N applied was greater than 34 kg ha-1. Nitrogen fertilization at 67 kg ha-1 per growing season provided an opportunity to maintain a balance between both yield and efficiency of N inputs. Results of this research highlight the interactions of N fertilization and harvest management have when optimizing yield of warm-season grasses grown as bioenergy feedstocks. List of acronyms: N, Nitrogen; PFP, partial factor productivity.Dr. Newell R. Kitchen, Thesis Supervisor.Includes bibliographical references

The macroeconomic cost of catastrophic pollinator declines

We develop a computable general equilibrium (CGE) approach to assess the macroeconomic impacts of productivity shocks due to catastrophic losses of pollination ecosystem services at global and regional scales. In most regions, producers of pollinator dependent crops end up benefiting because direct output losses are outweighed by increased prices, while non-agricultural sectors experience large adverse indirect impacts, resulting in overall losses whose magnitudes vary substantially. By comparison, partial equilibrium analyses tend to overstate the costs to agricultural producers, understate aggregate economy-wide losses, and overstate the impacts on consumers' welfare. Our results suggest an upper bound on global willingness to pay for agricultural pollination services of $127–$152 billion

Factor demand linkages, technology shocks, and the business cycle

This paper argues that factor demand linkages can be important for the transmission of both sectoral and aggregate shocks. We show this using a panel of highly disaggregated manufacturing sectors together with sectoral structural VARs. When sectoral interactions are explicitly accounted for, a contemporaneous technology shock to all manufacturing sectors implies a positive response in both output and hours at the aggregate level. Otherwise there is a negative correlation, as in much of the existing literature. Furthermore, we find that technology shocks are important drivers of the business cycle

Contributions of natural and human factors to increases in vegetation productivity in China

Increasing trends in vegetation productivity have been identified for the last three decades for many regions in the northern hemisphere including China. Multiple natural and human factors are possibly responsible for the increases in vegetation productivity, while their relative contributions remain unclear. Here we analyzed the long-term trends in vegetation productivity in China using the satellite-derived normalized difference vegetation index (NDVI) and assessed the relationships of NDVI with a suite of natural (air temperature, precipitation, photosynthetically active radiation (PAR), atmospheric carbon dioxide (CO2) concentrations, and nitrogen (N) deposition) and human (afforestation and improved agricultural management practices) factors. Overall, China exhibited an increasing trend in vegetation productivity with an increase of 2.7%. At the provincial scale, eleven provinces exhibited significant increases in vegetation productivity, and the majority of these provinces are located within the northern half of the country. At the national scale, annual air temperature was most closely related to NDVI and explained 36.8% of the variance in NDVI, followed by afforestation (25.5%) and crop yield (15.8%). Altogether, temperature, total forest plantation area, and crop yield explained 78.1% of the variance in vegetation productivity at the national scale, while precipitation, PAR, atmospheric CO2 concentrations, and N deposition made no significant contribution to the increases in vegetation productivity. At the provincial scale, each factor explained a part of the variance in NDVI for some provinces, and the increases in NDVI for many provinces could be attributed to the combined effects of multiple factors. Crop yield and PAR were correlated with NDVI for more provinces than were other factors, indicating that both elevated crop yield resulting from improved agricultural management practices and increasing diffuse radiation were more important than other factors in increasing vegetation productivity at the provincial scale. The relative effects of the natural and human factors on vegetation productivity varied with spatial scale. The true contributions of multiple factors can be obscured by the correlation among these variables, and it is essential to examine the contribution of each factor while controlling for other factors. Future changes in climate and human activities will likely have larger influences on vegetation productivity in China

Restless bandit marginal productivity indices I: singleproject case and optimal control of a make-to-stock M/G/1 queue

This paper develops a framework based on convex optimization and economic ideas to formulate and solve by an index policy the problem of optimal dynamic effort allocation to a generic discrete-state restless bandit (i.e. binary-action: work/rest) project, elucidating a host of issues raised by Whittle (1988)Žs seminal work on the topic. Our contributions include: (i) a unifying definition of a projectŽs marginal productivity index (MPI), characterizing optimal policies; (ii) a complete characterization of indexability (existence of the MPI) as satisfaction by the project of the law of diminishing returns (to effort); (iii) sufficient indexability conditions based on partial conservation laws (PCLs), extending previous results of the author from the finite to the countable state case; (iv) application to a semi-Markov project, including a new MPI for a mixed longrun-average (LRA)/ bias criterion, which exists in relevant queueing control models where the index proposed by Whittle (1988) does not; and (v) optimal MPI policies for service-controlled make-to-order (MTO) and make-to-stock (MTS) M/G/1 queues with convex back order and stock holding cost rates, under discounted and LRA criteria

Productivity in endowments : sectoral evidence for Hong Kong's aggregate growth

The author provides sectoral evidence that sheds new light on the current debate regarding the sources of growth of the East Asian miracle. The author tests both the productivity-driven and endowment-driven hypotheses using Hong Kong's sectoral data. The results show that most of the growth in the services sector is driven by the rapidly accumulating capital endowments, and not by productivity growth. In addition, productivity growth in the manufacturing sector is also unimpressive. The manufacturing sector is more labor intensive and its growth is hindered by the reallocation of resources into the services sector as a result of the growth of capital endowments and imports. Overall, sectoral evidence supports the endowment-driven hypothesis for Hong Kong's aggregate growth.Water and Industry,Banks&Banking Reform,Environmental Economics&Policies,Economic Theory&Research,Industrial Management,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform,Economic Growth,Industrial Management

Effects of nitrogen rates on grain yield and nitrogen agronomic efficiency of durum wheat genotypes under different environments

Durum wheat is an important staple food crop in Tunisia and other Mediterranean countries and is grown in various climatic conditions. Production and yield are however severely limited not only by drought events but also by reduced levels of nitrogen fertilisation. A study was carried out at two locations in the sub-humid area of Tunisia: Mateur in 2009–10 and 2010–11 and Beja in 2011–12 and 2012–13 under rainfed conditions. Four durum wheat genotypes (landraces: Bidi, Azizi; improved: Om Rabia, Khiar) were evaluated for nitrogen agronomic efficiency and related agronomic traits under various nitrogen rates: 0, 50, 100, 150, 200 and 250 kgNha−1, with three replications. There was a significant interaction effect (P ≤ 0.001) environments × genotypes ×N treatments for grain yield (GY), biomass yield (BY), harvest index (HI), partial factor productivity of applied nitrogen (PFPN) and nitrogen agronomic use efficiencies (NAE). GY was the most affected trait by nitrogen applied showing an increase of 94% under high N treatment (250 kgNha−1) compared to control plots without N treatments. A significant linear regression exists between GY (0 N) and GY for the different N rates (r =0.70; P < 0.001). This effect was more pronounced for improved genotypes than landraces for all parameters excepting BY and NAEBY. BY showed +11% increase in landraces than improved genotypes. PFPN showed an average decrease of 65% under high-N fertilisation with 10% prevalence for improved genotypes. Landraces tend to promote vegetative growth while grain filling efficiency was higher for improved genotype

UKERC Review of evidence for the rebound effect: Technical report 5: Energy, productivity and economic growth studies

This report forms part of the TPA’s assessment of evidence for a rebound effect from improved energy efficiency. Technical Report 5 focuses upon the relationship between energy, productivity and economic growth and examines the claim that improved energy efficiency will increase economy-wide energy consumption - the so-called ‘Khazzoom-Brookes postulate’