Rice is a staple food in high demand by households, but local production in Nigeria has not met the demand for rice consumption. The reasons for this were often connected with edaphic and human factors. This study therefore, examined soil and socio-economic constraints to irrigated rice production in the Kano River Project Phase I. The objectives were to: (i) assess the nature and variation in physico-chemical properties of soils in the study area; (ii) examine the relationship between input costs and net-profit of irrigated rice production systems; (iii) assess the constraints of rice farming; (iv) examine the factors that affect farmersâ€™ adjustments to project inputs recommendation for rice farming; and (v) assess the sustainability and optimization of irrigated rice production systems. Purposive sampling technique was used to select two irrigated soil units in Kura and Bunkure irrigation layouts. Ten hectares were demarcated on Pab and Pab/Pb Complex soils in the two layouts and their corresponding adjacent non-irrigated lands for comparison. Purposive sampling was also used to pick 10 of the 58 settlements in the study area. Copies of a structured questionnaire were administered to 1,730 registered irrigated rice farmers in the two soil units. Descriptive and inferential statistics including simple percentages and goal programming were employed. The findings of the study were that the soils are generally sandy (69% to 79%). All the parameters of the two irrigated soil units exhibited homogeneity (C.V < 33%). Eight of the twenty-one soil parameters in irrigated soil were not significantly different from non-irrigated soil in Pab soil of Kura (p < 1.73), but in Bunkure only six parameters were not different (p < 1.73). Five soil parameters each in irrigated Pab/Pb complex soil of Kura and Bunkure were not different (p < 1.73 ) from those in non-irrigated fields, the other sixteen parameters were significantly different (p >1.73 ); there is positive correlation (r = 0.52) between rice input costs and net-profit. Covariance analysis showed positive linear relationship in eight rice-farming settlements (Kura +834,785,050.54, Bunkure +209,427,795.38, Danhasan +1,760,623,900.02, Yadakwari +120,170,201.29, Gafan +732,997,522.32, Imawa +401,864,387.19, Kosawa +1,474,231,798.99, Makwaro +127,780,984.59) and negative in two Babbabgiji -707,072,102.23 and Kadawa -192,341,627.88); nitrogen (0.06g/kg-1) and organic matter (0.8g/kg-1) fell below threshold levels of 2.0g/kg-1 and 68.8 g/kg-1, respectively and the factors that affect farmersâ€™ adjustments to project inputs recommendation for rice farming; inputs costing (24.54%), farming knowledge (21.50%), technical farming experience (16.24%), modern techniques (16.21%) and labour input (10.30%) were the factors that contributed 88.77% of the input variance adjustment to rice production; and sustainability index (Z0 = 348 > 0) indicated that the present irrigated rice production system is not sustainable. Optimization procedure showed that 97.13% sustainability in rice production can be achieved. The study concluded that irrigated rice production in the Kano River Project I were constrained by soil nitrogen, organic matter content and five socio-economic factors. It is therefore recommended that nitrogen, organic matter input optimizations coupled with education of farmers on modern input techniques should be improved.