Lal K. Almas

AGRONOMIC EFFICIENCY AND PROFITABILITY OF P-FERTILIZERS APPLIED AT DIFFERENT PLANTING DENSITIES OF MAIZE IN NORTHWEST PAKISTAN

The use of appropriate source of phosphorus (P) fertilizer at different planting densities has considerable impact on growth, grain yield as well as profitability of maize (Zea mays L). Field experiment was conducted in order to investigate the impact of P sources [(S0 = P not applied, S1 = SSP (single super phosphate) S2 = NP (nitrophos), and S3 = DAP (diammonium phosphate)] on maize growth analysis, yield and economic returns planted at different planting densities (D1 = 40,000, D2 = 60,000, D3 = 80,000, and D4 = 100,000 plants ha−1) at the New Developmental Agricultural Research Farm of Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan, during summer 2006. This paper reports the profitability data with two objectives: 1) to compare agronomic efficiency and profitability of P-fertilizers, and 2) to know whether plant densities affect agronomic efficiency and profitability of P-fertilizers. Application of DAP and SSP resulted in higher partial factor productivity (PFP) (63.58 and 61.92 kg grains kg−1 P), agronomic efficiency (AE) (13.01 and 13.71 kg grains kg−1 P) and net returns (NR) (Rs. 16,289 and 16,204 ha−1), respectively, while NP stood at the bottom in the ranking with lower PFP (57.16 kg grains kg−1 P), AE (8.94 kg grains kg−1 P) and NR (Rs. 4,472 ha−1). Among the plant densities, D3 stood first with maximum PFP (69.60 kg grains kg−1 P), AE (18.21 kg grains kg−1 P) and NR (Rs. 21,461 ha−1) as compared to other plant densities. In conclusion, the findings suggest that growing maize at D3 applied with either SSP or DAP is more profitable in the wheat-maize cropping system in the study area.

Groundwater Policy Research: Collaboration with Groundwater Conservation Districts in Texas

The unique nature of the Ogallala Aquifer presents interesting and confounding problems for water policymakers who are coping with changing groundwater rules in Texas. The purpose of this article is to link previous efforts in water policy research for the Ogallala Aquifer in Texas with current collaborations that are ongoing with regional water planners. A chronological progression of economic water modeling efforts for the region is reviewed. The results of two recent collaborative studies are presented that provide estimates of impacts of alternative policies on groundwater saturated thickness, water use, net farm income, and regional economic activities.

Integrating Stakeholder Input into Water Policy Development and Analysis

Agricultural water use is becoming an issue in much of the South due to population growth. Results of projects evaluating the impacts of conservation strategies aimed at reallocating or extending the life of water supplies are being met with great skepticism by stakeholder groups. In order to gain acceptance of results, it is essential that stakeholder groups be involved from the beginning in the identification of potential water conservation strategies and be kept informed throughout the project. The objective of this paper is to review previous attempts at involving stakeholders and the methodology currently being employed in the Ogallala Aquifer Project.

Feasibility of Water Management Strategies for the Declining Ogallala Aquifer

BACKGROUND The Region A groundwater aquifer level in the heavily irrigated, northern region of Texas continues to decline with this portion of the Ogallala Aquifer having no appreciable rate of recharge. The new state water planning requirements warranted a feasibility analysis of water management strategies that could be potentially implemented during the next 60 years to reduce the rate of aquifer pumpage for irrigation use. The strategies proposed in Senate Bill 1 were those of ET network scheduling, changes in crop variety, irrigation equipment improvements, changes in crop type, implementation of conservation tillage methods, precipitation enhancement, and the conversion from irrigated to dryland farming.

The Feasibility of Variable Rate Irrigation with Center Pivot Systems in the Northern Texas High Plains

A thorough site-specific assessment of the economic viability of Precision Agriculture Technology must be conducted prior to producer adoption. In the semi-arid region of the Texas High Plains, research has shown that no production input is more important than water. The majority of irrigation water in this region is applied using center pivots. In this paper, the feasibility of using variable rate irrigation (VRI) technology on these center pivot systems is assessed using actual yield maps from producers within the region.. Analysis of producer yield maps indicate that many producers have enough yield variability to justify the investment of VRI technology. A simple process is illustrated for assessing the required variability using commercial, yield-mapping software. Discussion of the necessary variability distribution for feasibility is included. The impact of commodity prices on the economic feasibility of VRI technology is also mentioned.

Modeling Groundwater Levels in the Northern High Plains of Texas

Future changes in groundwater policy and the use of alternative technologies will have to be adopted for the Northern High Plains of Texas due to the depleting underlying Ogallala aquifer, the major source of water for irrigation. The objective of this study was to calibrate and validate an integrated regional groundwater model using observed groundwater levels between 1939 and 2007 in four heavily irrigated counties (Dallam, Sherman, Hartley, and Moore counties) located in the northwest corner of the Northern High Plains of Texas. For this purpose, the study area was divided into 1km cells and the MODFLOW-2000 model was calibrated and validated. Results indicate that the groundwater model was calibrated and validated satisfactorily by reproducing and comparing groundwater levels with correlation coefficients of 0.98 in both cases and with normalized root mean square errors of 5.0% and 4.3% respectively. The calibrated model is being used to evaluate the implications of five different agricultural management policy scenarios on groundwater levels between 2010 and 2060. Simulation results should assist water planners to estimate specific irrigation water uses and promote the use of alternative technologies in the 4-county area, and to potentially implement new policies for sustainable development of the Ogallala aquifer.

Using Climatic Data and Evapotranspiration Requirements to Estimate Corn Production Profitability with Optimal Irrigation Levels in the Texas Panhandle

The performance of the agricultural sector in the Texas Panhandle is dependent on irrigation. The declining availability of irrigation water from the Ogallala aquifer combined with increasing energy costs make irrigation strategies much more critical. Economic viability and resource conservation are not mutually exclusive. Selecting an irrigation level maximizes profits both increases profits and conserves the water resource as compared with a strategies of maximizing yield per acre. Under average precipitation, a management strategy that irrigates to maximize yield reduces profit by between

A STATISTICAL MODEL USING REFERENCE EVAPOTRANSPIRATION AND WEATHER DATA TO PREDICT THE ECONOMIC OPTIMAL IRRIGATION LEVEL FOR CORN PRODUCTION IN THE TEXAS PANHANDLE

22 and

Timing and rate of nitrogen application influence profitability of maize planted at low and high densities in Northwest Pakistan.

158 per acre and increases water consumption by 2.21 and 11.20 acre inches depending on the combination of corn and natural gas prices. Adopting a profit maximizing strategy is a win-win situation both economically and for water resource conversation.

Economic Optimization of Groundwater Resources in the Texas Panhandle

Corn yield and evapotranspiration (ET) data obtained from weighing lysimeters is accumulated from nine experiments over six years and used to estimate a response function. The quadratic response function of corn yield as a function of water use by the plants indicates that yield increases at a decreasing rate as ET increases. Extending the analysis to water application data by commercial producers in a thirteen county area in the Texas Panhandle provides a response function of yield as a function of water application to meet ET needs. The best estimate of the relationship is a quadratic function. The response function is transformed into a value function measuring the value of corn produced corresponding to different levels of water availability. The cost function is estimated in terms of the energy cost for irrigation. These value and cost functions are then used to determine the profit maximizing level of water application for various price levels for corn and natural gas.