An Asian Journal of Soil Science

S. Srinivasan ¹, A. Angayarkanni ¹

Affiliations
1 Department of Soil Science and Agricultural Chemistry, Annamalai University, Annamalainagar (T.N.), IN

Abstract

Soil test crop response (STCR) correlation studies were conducted by gradient crop experiment-rice (ADT43) and then Test crop experiment-rice (ADT-36) at an Experimental Farm, Annamalai University, Annamalainagar. The field layout comprised four strips (I, II, III & IV), in which the needed variation in soil fertility for potassium was deliberately created (Dev et al., 1978). After the harvest, each gradient strip was divided into 24 plots which were received 5 levels of nitrogen @ (0, 50, 100, 150 & 200 kgha^-1), four levels of phosphorus (0, 30, 60 and 90 kgha^-1), three levels of potassium (0, 40 and 80 kgha^-1), Two levels of FYM (0.1, 2.5 t/ha^-1) and Azospirillum levels were (0, 2 kgha^-1) (Fractional Factorial Randomized Block Design). Rice(ADT-36) was grown as the test crop. At harvest, grain yield ,K uptake, initial soil available K status and fertilizer K₂O applied were noted plot-wise. The NR kgq^-1, CS% and CF% values for potassium were 1.50, 10.67 and 54.05, respectively. The per cent contribution of K from FYM and FYM+Azospirillum were found to be 28.79 and 29.72, respectively. These data have been transformed in the form of simple equations. The results revealed that at an initial soil available potassium status was 350 kgha^-1, the FK₂O requirement to get an yield target of 70 qha^-1 of rice was 111 kgh^-1 with fertilizer alone, whereas the FK₂O requirement reduced to 86 kgha^-1 with fertilizer+FYM+Azospirillum application.

Keywords

STCR, Rice, Fertilizer Potassium Doses, INM.

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S. Srinivasan ¹, A. Angayarkanni ¹

Affiliations
1 Department of Soil Science and Agricultural Chemistry, Annamalai University, Annamalainagar (T.N.), IN

Abstract

With a view to assess the extent of fertilizer phosphorus requirement for an yield target of 70 qha^-1 of rice(ADT-36) during kharif season, the gradient experiment-rice (ADT-43) followed by test crop experiment-rice (ADT-36) were conducted on Vertisol based on STCR approach. Making use of the data generated from field experiment, basic parameters were estimated, fertilizer adjustment equations were developed. The basic data obtained as NR qha^-1, %CS and %CF for phosphorus were 12.53, 61.07 and 10.67, respectively. The efficiency of FYM with respect to P was 16.48. The results revealed at 20 kg soil available phosphorus ha^-1, the fertilizer P requirement was 100 kgha^-1. With the conjoint use of FYM, the fertilizer P dose was reduced to 87 kgha^-1.

Keywords

STCR, Rice, Fertilizer Adjustment Equations, Fertilizer, Phosphorus Doses.

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S. Srinivasan ¹, A. Angayarkanni ¹

Affiliations
1 Department of Soil Science and Agricultural Chemistry, Annamalai University, Annamalainagar (T.N.), IN

Abstract

A field experiment was carried out at an Experimental Farm, Annamalai University, Annamalainagar. The needed variation in soil fertility was deliberately created by dividing the field into 4 equal strips viz., I, II, III and IV. An exhaust crop of rice cv. ADT-43 was grown to enable through interaction between the nutrients in soil and added fertilizers. After the harvest, each gradient strip was divided into 24 plots. Treatments consisted of 5 levels of N (0, 50, 100, 150 & 200 kg ha^-1), 4 levels of P₂O₅ (0, 30, 60 and 90 kg ha^-1), 3 levels of K₂O (0, 40 and 80 kg ha^-1), 2 levels of FYM 0, 12.5 t/ha^-1 and 2 levels of Azospirillum, 0, 2 kg ha^-1 (Fractional Factorial Randomized Block Design). Rice (ADT-36) was grown as the test crop. At harvest, by using grain yield, N uptake, initial soil available N status and fertilizer doses applied the basic data viz., nutrient requirement kg ha^-1, soil and fertilizer nutrient efficiencies (%) were estimated for making fertilizer N recommendation. There was considerable reduction in the quantities of fertilizer N due to IPNS.

Keywords

STCR, Rice, IPNS, Fertilizer Adjustment Equations, FN Prescriptions.

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T. Alagu Nagendran ¹, A. Angayarkanni ¹

Affiliations
1 Department of Soil Science, Annamalai University, Annamalainagar (T.N.), IN

Abstract

The water retention characteristics of soils in a toposequence in Cumbum valley of Tamil Nadu revealed that water retention decreased with increasing soil moisture suction. The water retentivity at 0.03 and 1.5 MPa tensions was significantly and positively correlated with clay, clay plus silt, and CEC but negatively with sand content. The effect of organic carbon on water retentivity, both at 0.03 and 1.5 MPa tensions was non-significant. The soils with high clay content had more water storage capacity showing their potential for growing two crops in a year whereas the shallow ischolar_mained annual crops may be the best option for shallow soils with relatively low clay content and lower moisture retention capacity.

Keywords

Soil Properties, Clay Content, Water Storage Capacity, Alternate Crop.

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