Rotation and tillage effects on yield of pearl millet (Pennisetum glaucum) and cowpea (Vigna unguiculata), and aspects of crop water balance and soil fertility in a semi-arid tropical environment

1995 ◽  
Vol 124 (1) ◽  
pp. 39-44 ◽  
Author(s):  
M. C. Klaij ◽  
B. R. Ntare

SUMMARYA 4-year field experiment was conducted from 1986 to 1989 in Niger to determine the effects of pre- and post-harvest tillage and rotation of pearl millet (Pennisetum glaucum (L). R. Br.) and cowpea (Vigna unguiculata (L.) Walp.) on crop yield, crop water use and soil fertility on a sandy soil. Presowing tillage increased grain and crop residue yields over the traditional system of no tillage. Post-harvest tillage resulted in lower yields than pre-sowing tillage during the last 2 years of the experiment. Millet-cowpea rotation increased yield and there were no important tillage × rotation interactions. Crop water use was similar for a dry and a wet year, but less water was held in the profile after the harvest of cowpea. Compared to pre-sowing tillage and no tillage, post-harvest tillage increased the amount of water conserved until the next season. In all treatment combinations, soil organic matter and total N content both declined on average by 62%, and soil pH (KCI) decreased from 4·6 to 4·3.

1981 ◽  
Vol 17 (4) ◽  
pp. 1095-1108 ◽  
Author(s):  
J. E. Burt ◽  
J. T. Hayes ◽  
P. A. O'Rourke ◽  
W. H. Terjung ◽  
P. E. Todhunter
Keyword(s):  

1983 ◽  
Vol 34 (6) ◽  
pp. 661 ◽  
Author(s):  
RJ Lawn

The effect of spatial arrangement and population density on growth, dry matter production, yield and water use of black gram (Vigna mungo cv. Regur), green gram (V. radiata cv. Berken), cowpea (V. unguiculata CPI 28215) and soybean (Glycine rnax CP126671), under irrigated, rain-fed fallowed and rain-fed double-cropped culture was evaluated at Dalby in south-eastern Queensland. Equidistant spacings increased initial rates of leaf area index (LAI) development and crop water use compared with 1-m rows at the same population densities. In the irrigated and rain-fed fallowed treatments, where more water was available for crop growth, both seed yields and total crop water use were higher in the equidistant spacings. However, in the double-cropped treatment, where water availability was limited, there was no yield difference between rows and equidistant spacings, primarily because initially faster growth in the latter was offset by more severe water stress later in the season. Higher population density also increased initial crop growth rate and water use, particularly in the equidistant spacings. However, there was no significant yield response to density, presumably because subsequent competition for light/ water offset initial effects on growth. Although absolute yield differences existed between legume cultivars within cultural treatments, there were no significant differential responses to either spatial arrangement or population density among these four cultivars.


2017 ◽  
Vol 113 (7/8) ◽  
Author(s):  
Abiodun A. Ogundeji ◽  
Henry Jordaan

Climate change and its impact on already scarce water resources are of global importance, but even more so for water scarce countries. Apart from the effect of climate change on water supply, the chill unit requirement of deciduous fruit crops is also expected to be affected. Although research on crop water use has been undertaken, researchers have not taken the future climate into consideration. They also have focused on increasing temperatures but failed to relate temperature to chill unit accumulation, especially in South Africa. With a view of helping farmers to adapt to climate change, in this study we provide information that will assist farmers in their decision-making process for adaptation and in the selection of appropriate cultivars of deciduous fruits. Crop water use and chill unit requirements are modelled for the present and future climate. Results show that, irrespective of the irrigation system employed, climate change has led to increases in crop water use. Water use with the drip irrigation system was lower than with sprinkler irrigation as a result of efficiency differences in the irrigation technologies. It was also confirmed that the accumulated chill units will decrease in the future as a consequence of climate change. In order to remain in production, farmers need to adapt to climate change stress by putting in place water resources and crop management plans. Thus, producers must be furnished with a variety of adaptation or management strategies to overcome the impact of climate change.


2012 ◽  
Vol 76 (2) ◽  
pp. 607-616 ◽  
Author(s):  
Judy A. Tolk ◽  
Steven R. Evett

2018 ◽  
Vol 10 (12) ◽  
pp. 1867 ◽  
Author(s):  
Bruno Aragon ◽  
Rasmus Houborg ◽  
Kevin Tu ◽  
Joshua B. Fisher ◽  
Matthew McCabe

Remote sensing based estimation of evapotranspiration (ET) provides a direct accounting of the crop water use. However, the use of satellite data has generally required that a compromise between spatial and temporal resolution is made, i.e., one could obtain low spatial resolution data regularly, or high spatial resolution occasionally. As a consequence, this spatiotemporal trade-off has tended to limit the impact of remote sensing for precision agricultural applications. With the recent emergence of constellations of small CubeSat-based satellite systems, these constraints are rapidly being removed, such that daily 3 m resolution optical data are now a reality for earth observation. Such advances provide an opportunity to develop new earth system monitoring and assessment tools. In this manuscript we evaluate the capacity of CubeSats to advance the estimation of ET via application of the Priestley-Taylor Jet Propulsion Laboratory (PT-JPL) retrieval model. To take advantage of the high-spatiotemporal resolution afforded by these systems, we have integrated a CubeSat derived leaf area index as a forcing variable into PT-JPL, as well as modified key biophysical model parameters. We evaluate model performance over an irrigated farmland in Saudi Arabia using observations from an eddy covariance tower. Crop water use retrievals were also compared against measured irrigation from an in-line flow meter installed within a center-pivot system. To leverage the high spatial resolution of the CubeSat imagery, PT-JPL retrievals were integrated over the source area of the eddy covariance footprint, to allow an equivalent intercomparison. Apart from offering new precision agricultural insights into farm operations and management, the 3 m resolution ET retrievals were shown to explain 86% of the observed variability and provide a relative RMSE of 32.9% for irrigated maize, comparable to previously reported satellite-based retrievals. An observed underestimation was diagnosed as a possible misrepresentation of the local surface moisture status, highlighting the challenge of high-resolution modeling applications for precision agriculture and informing future research directions. .


2014 ◽  
Vol 52 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Agung Putra PAMUNGKAS ◽  
Kenji HATOU ◽  
Tetsuo MORIMOTO

Geoderma ◽  
2018 ◽  
Vol 327 ◽  
pp. 13-24 ◽  
Author(s):  
Mukhtar Ahmad ◽  
Debashis Chakraborty ◽  
Pramila Aggarwal ◽  
Ranjan Bhattacharyya ◽  
Ravender Singh

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