Introduction
Rice (Oryza sativa L.) is grown on 2.3 Mha alluvial, calcareous, low organic matter soils, with an average paddy yield of 2.00 t ha-1. One major cause of low rice productivity – compared with much higher potential yields – remains imbalanced nutrient management. In the literature, rice is categorized as tolerant to boron (B) deficiency. However, in consideration of widespread B deficiency observed in many other crops in the country, NARC soil scientists suspected B deficiency to be amongst the causes of low rice yields, and, therefore, undertook field and laboratory research to investigate the hypothesis.
Technology Development, Demonstration and Recommendation
During 2001-2004, multi-location field research in major rice growing areas of the Punjab has led to the theoretically-unexpected identification and establishment of widespread and severe incidence of B deficiency in rice cvs. Super Basmati, Basmati-385 and KSK-282. Concurrent, extensive field research in Sindh revealed that B deficiency is an equally serious problem in rice cv. IR-6. Fertilizer B use (@ 0.75 kg B ha
The technology has been extensively field demonstrated in Punjab (in collaboration with Adaptive Research) and Sindh (with Engro Chemical Pakistan Ltd.) – with affirmative results throughout. Consequently, use of B in rice was recommended by the Punjab Agriculture Department in 2005.
The Technology
The recommended dose of 0.75 kg B ha-1 (i.e., 3.0 kg Borax Acre-1 or 2.0 kg Granubor
Acre-1) is applied along with other fertilizers prior to rice transplanting. Uniform field broadcast of the small quantity of Borax powder must be ensured by pre-mixing of with 4-5 times volume of well pulverized soil or Granubor granulesby mixing with other granular fertilizers. Boron use in rice crop leaves a beneficial residual effect on wheat in the rotation.
Key References
Rashid, A., M. Yasin, M. A. Ali, Z. Ahmad, and R. Ullah. (2006) An alarming boron deficiency in calcareous rice soils of Pakistan: Boron use improves yield and cooking quality. Proc 3rd Int Symp on All Aspects of Plant and Animal Boron Nutrition, Wuhan, China, 9–13 Sep 2005. Springer, Dordrecht.
Rashid, A., M. Yasin, M. Ashraf, and R. A. Mann. (2004) Boron deficiency in calcareous soils reduces rice yield and impairs grain quality. International Rice Research Notes 29: 58–60.
