Effect of crop geometry and in situ soil moisture conservation practices on yield attributes and yield of upland rice (Oryza sativa L.)

2021 ◽  
Vol 58 (1) ◽  
pp. 26-32
Author(s):  
Gunturi Alekhya ◽  
V Jayakrishnakumar

Rice is the most widely grown crop in India. With the decreasing availability of water for irrigation, farmers are now switching towards water efficient production systems such as upland rice. Moisture stress at critical stages is one of the major reasons for low productivity of upland rice. So, the present study was conducted at college of Agriculture, Vellayani, Thiruvananthapuram, Kerala Agricultural University, Kerala, India. The experiment was conducted in RBD with nine treatments including two crop geometries viz., normal planting (20 cm x 10 cm) and paired row planting (10 cm x 10 cm) with 40 cm between paired rows, three rows of cowpea are grown in between two paired rows and in situ soil moisture conservation practices viz., live mulching of cowpea, hydrogel application and coirpith compost application were compared and analysed statistically on yield parameters and yield. Results revealed that, the treatment T9 (Paired row planting with live mulching of cowpea, hydrogel and coir pith compost application) favorably influenced the yield characters and yield of upland rice through proper conservation of moisture and improved availability of nutrients. The treatment T9 recorded the highest grain and straw yields of 3825 and 7700 kg ha-1 respectively with a harvest index (0.48) and was significantly superior to other treatments. It also recorded the highest moisture content in the soil as well as the maximum uptake and availability of nutrients.

2009 ◽  
Vol 6 (8) ◽  
pp. 1423-1444 ◽  
Author(s):  
T. Keenan ◽  
R. García ◽  
A. D. Friend ◽  
S. Zaehle ◽  
C. Gracia ◽  
...  

Abstract. Water stress is a defining characteristic of Mediterranean ecosystems, and is likely to become more severe in the coming decades. Simulation models are key tools for making predictions, but our current understanding of how soil moisture controls ecosystem functioning is not sufficient to adequately constrain parameterisations. Canopy-scale flux data from four forest ecosystems with Mediterranean-type climates were used in order to analyse the physiological controls on carbon and water flues through the year. Significant non-stomatal limitations on photosynthesis were detected, along with lesser changes in the conductance-assimilation relationship. New model parameterisations were derived and implemented in two contrasting modelling approaches. The effectiveness of two models, one a dynamic global vegetation model ("ORCHIDEE"), and the other a forest growth model particularly developed for Mediterranean simulations ("GOTILWA+"), was assessed and modelled canopy responses to seasonal changes in soil moisture were analysed in comparison with in situ flux measurements. In contrast to commonly held assumptions, we find that changing the ratio of conductance to assimilation under natural, seasonally-developing, soil moisture stress is not sufficient to reproduce forest canopy CO2 and water fluxes. However, accurate predictions of both CO2 and water fluxes under all soil moisture levels encountered in the field are obtained if photosynthetic capacity is assumed to vary with soil moisture. This new parameterisation has important consequences for simulated responses of carbon and water fluxes to seasonal soil moisture stress, and should greatly improve our ability to anticipate future impacts of climate changes on the functioning of ecosystems in Mediterranean-type climates.


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