Management Option In Relation To Weather Adjustment
While in irrigated condition timeliness of irrigation is important for higher production, a number of options such as choice of suitable crops and varieties, alternate crop strategies, mid season correction, crop life saving measures, alternate land use systems etc. are to be adopted in rained agriculture to adjust to aberrant weather conditions.
Suitable cropping systems aiming to adjust or reduce the intra – seasonal impact of climatic variability should be based on inter – seasonal variability of rainfall the water deficiency and the length and characteristics of growing season.
In arid and semi – arid region of Hyderabad, the length of growing season varies from 15 to 30 weeks with variation in rainfall and soil moisture storage capacity (Table 6). In soils having medium available water storage capacity (150 mm in the soil profile) a crop with a 19 weeks growing season is likely to have adequate moisture only coce in 4 years. Under such conditions.
Table 6 Length of the growing season (week) for three soil conditions Hyderabad.
Growing Season (weeks)
Available water storage capacity (mm)
Low (50 mm)
Medium (150 mm)
High (300 mm)
(Source : Virmani – 1989)
From seed germinating rains 25 June to put of season (time when profile moisture reduces AET / PET ratio of Actual evaportanspiration to potential evapotranspration to 0.5 )
* Low : shallow Altisol : medium : shallow to medium – deep Vertisols : high deep vertisoils.
intercropping of a short duration sorghum (105 – 110 days) with a long our at lon pigeonpa (150 – 180 days) yielded a land equivalent ratio of 1966. Pan and willey 1981). Thus, in case of random variability of rainfall, intercropping increases crop yield as well as provides stability. Based on 89 sorghum pigeonpea intercrop experiments conducted in diverse environments. It was been observed that on an average intercropping yielded equivalent of 90 mm solv sorghum yield and about 25% of sole pigeonpea yield.
Choice of the right intercropping will depend of the awards distribution pattern and soil moisture storage. In areas having be ental rainfall in the early part of the growing season drought tolent be (pigeonpea) may be useful. If rainfall is undertain is the later part of the growing season, then intercrop spould be storter in than the base crop Considering the high valves of pulses and outseeds and their soil restoring ability, these crops shouln find a place in any probulable intercropping programme.
Intercropping of pearl millet + pigeonpea (2:1) and sunflower + pigeonpea (2: 1) on medium deep soils are ideally suited for dryland conditions (Jadhav et.al., 1991) due to large difference in maturity periods of component crops which useful for harvesting the natural resources like solar rediation, soil moisture and nutrients more efficiently.
Table 7. Mean grain yield kg. ha-1, LER and gross monetary returns (Rs. ha-1) as influenced by treatements (Pooled data of 3 years : 1985 – 1988).
Pearl millet + pigeonpea
Sunilower + pigeonpea
Sole pearl millet
C.D. (p 0.05)
(Source : Jadhav et. al., 1991)