Simulating yields of sorghum and pearl millet in the semi-arid tropics

A sorghum simulation model, SORGF, was revised for use in the semi-arid tropics. As a result of the revisions in the model, the correlation coefficient between observed and simulated grain yield of sorghum (n=59) increased from 0.52 to 0.86. Comparison between simulated and observed grain yields showed that the SORGF model can be used to estimate sorghum yields with reasonable accuracy before harvest. Responses of sorghum to drought-stress and to changes in plant density were simulated. The correlation coefficient between observed and simulated sorghum grain yield data pooled over five levels of plant density and two cultivars was 0.91. The correlation coefficient between observed and simulated sorghum grain yield data pooled over two water treatments, two cultivars, and two seasons was 0.92. The model was used to compute the probabilities of simulated sorghum grain yield and the requirements of N-fertilizers based on 30 years of climatic data for four locations in India. A simulation model for pearl millet was developed following an approach similar to that of SORGF. The pearl millet model was tested against independent data; further testing of the pearl millet model is required before its application

Evaluation of SORGF Subroutines - A Consultancy Report

In the seasonally dry rainfed semi-arid tropics (SAT) crop yields are generally low and variable from year to year. The task of improving and stabilizing agricultural production in the SAT is complicated by the presence of several constraints in these areas. However, lack of water is the key limiting factor for crop production in the SAT (Virmant et al., 1980). Attempts are made through interdisciplinary research to increase and stabilize agricultural production through improved soil, water and crop management practices..

Simulating Growth and Yield Responses of Sorghum to Changes in Plant Density

Though numerous field experiments have been conducted on the effects of plant density on growth and yield of sorghum [Sorghum bicolor (L.) Moench], tests showing the ability and validity of a sorghum simulation model to respond to changes in plant density have not been reported previously. Thus, a field experiment was conducted at ICRlSAT Center, Patancheru, India, in the 1983 rainy season on a Vertisol (fine, clayey, montmorillonitic, isohyperthermic Typic Pellustert) to test the validity of the sorghum simulation model, SORGF, for simulating the effect of plant density on growth and development of sorghum. Simulations were compared to data collected on phenology, leaf area indices (MI), total dry matter (TDM), and grain yield for five plant densities (4, 8, 12, 16, and 20 plants m−2) of two sorghum cultivars (CSH 6 and SPV 351). Observed TDM and grain yield increased up to 16 plants m−2, while simulated TDM and grain yield increased up to 20 plants m−2. The model, on average, underestimated TDM by 8% and overestimated grain yield by 2%. Good agreement between observed and simulated LAI, TDM, and grain yield across five plant densities and two cultivars was supported by the insignificant differences of observed and simulated values from a one-to-one line. The model was further validated using climatic data from the ICRISAT Center between 1976 and 1984. Simulated grain yield using plant densities of 12 plants m−2 were within 3% in 6 yr and between 11 and 20% in the other 3 yr of observed data using plant densities of 13 plants m−2. Results from this study suggest that the SORGF model appears useful for simulating the effect of plant density on the growth and yield of wellmanaged sorghum when input data on cultivar, climate, soil, and agronomic management are available

Agrometeorological aspects of crop yield modeling: data needs and limitations

Agrometeorological analysis and crop yield modeling can help determines operations aimed at increasing and establishing agricultural production..

Agroclimatological characteristics of Chickpea and Groundnut Growing areas in India

Chickpea is grown in a wide range of agroclimatic environments (Sinha 1977)* and their yield potential exceeds 4 t ha-1 (Nene 1986). However* the yields achieved by farmers are quite low and variable. Based on chickpea production data (FAO 1982)» there are 37 chickpea growing countries. The total chickpea production in the world for 1982 was 6.2 million t. India produced 74% of the world production. Chickpea is usually grown after the rainy season on stored soil moisture* during winter in the .tropics and in the spring in temperate and mediterranean regions. Chickpea has been recently grown in temperate and mediterranean regions as a winter crop when rainfall was well distributed during the growing period (Saxena 1984)

Health utilities and costs for neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare, neurological disease that places a significant burden on patients, their carers, and healthcare systems

Crop simulation models and some implications for agroforestry systems

ICRISATs work on nlodeling sosorghrrm, pearl millet, and groundnrrt is summarize4 and flle inlplications foragroforeshysystems an mmined. Trees can improve waterinjiltration and ufiliied eeprpmjile water not accrssible to con~mtionalc rops. In thispaper we have shrdied how the bttroduction of tree species in crop systenls m,ottld affect overall water use a~~dproditctivitIV).e haw analp-d climatic data ojfive selecfed locations in arid and semi-arid India in terms oJt1te distribution and dependability ofrainfoll and the trend in seasonal rainJatlpatten1 in the recent years. Pmbabililies oJavailable soil water are simlrlated for these locations. Available waler holdi~tgcapacityo fthesoils are assumedas 25,50,100, and l5Omm at each oftheselected locations to accortnt soilsfor ratcging from very shallow lo medirrm deep. Grain yields and total drynratterare si~nrtlatedfort hese agroclimatic conditions to outline the environmeqts where agroloresty is feasible. Grain yields and total dry matter oJtlte crops at various le~*elosf shading by the treeconlponent are sintrrlated. =se results are qected to giw some insight as to how the tree-ntanagement will am1 the microclintale and productivity of the crop. Effects of changes in niicroclimale such as canopy temperature and radiation intercepted (by manipnlatbrgrow widrh, plant dettsir);canopygrowrhJ on productivity based on information from intercroppC~gandJorestystudiesa rediscussed Simulation mulfsarec ornpared wit11 tlte crperintental data from ICRlSAT and elsewhere on appropriate cropping systems under various agroclimatic conditions. hfinimunt data sets that need to br coNecledfrom specijc qerimcnfs designed for agrajoresty sfudies are identified

Variability of rainfall and soil water in the dry tropics: A case study for selected locations of India, Niger and Botswana

The objectives of the study were to examine the variability of rainfall and soil moisture availability of three diverse locations in dry tropica, i.e. Hyderabad in India..

Agroclimatic Environment of Chickpea and Pegeonpea

Meteorological data for four contrasting chickpea-growing locations--Hisar and Hyderabad in India, Aleppo in Syria, and Khartoum in Sudan are given. In India, pigeonpea-growing areas are usually located in regions with a 600-1400 mm annual rainfall and a growing period of 90-180 days. Chickpea is usually grown where mean daily maximum temperatures are 22.5-30 degrees C and mean daily minimum temperatures 7.5-13 degrees C during January, when flowering begins. The soils on which the two crops are grown are predominantly Alfisols, Entisols, Inceptisols, and Vertisols. At Patancheru, in a medium-deep Vertisol having 150 mm water-storage capacity, the simulated available soil water in 70% of the years studied was 120 mm under rainy-season fallow and 80 mm under rainy-season sorghum. At Hisar, the simulated available soil water after rainy season fallow in 70% of the years was more than 120 mm in soils with 150 mm water-storage capacity. Using the water use and yield relationship, cumulative probabilities of chickpea yields and phosphorus requirements were computed for both ICRISAT Center and Hisar. Although simulated yields were higher than farmers' yields, the water use and yield relationships can be used to compute the probabilities of potential yield at various locations. The delineation of the isoclimes of pigeonpea-growing areas in West Africa is also reported